EclipseCon 2008

I am very happy to tell you that two of my proposed sessions are accepted for presentation at EclipseCon 2008 in Santa Clara. The first one ("Spring OSGi Reloaded") is an updated version of last years tutorial about the combination of Spring and OSGi technology (now called Spring Dynamic Modules for OSGi Service Platforms). And I am very happy to be part of the tutorial team consisting of BJ Hargrave, Adrian Colyer, Bernd Kolb and myself. The second one is a short talk about "Lessons Learned from Adopting The Eclipse Way" for general in-house software projects.

I am very happy to tell you that two of my proposed sessions are accepted for presentation at EclipseCon 2008 in Santa Clara. The first one ("Spring OSGi Reloaded") is an updated version of last years tutorial about the combination of Spring and OSGi technology (now called Spring Dynamic Modules for OSGi Service Platforms). And I am very happy to be part of the tutorial team consisting of BJ Hargrave, Adrian Colyer, Bernd Kolb and myself. The second one is a short talk about "Lessons Learned from Adopting The Eclipse Way" for general in-house software projects.

EclipseCon 2008

Excellent Talk about Simplicity

In general I don't like to write too positive about things that happens within my company. This often sounds like pure advertisement for the company business and therefore I don't like it for my private blog. But today I need to make an exception. Not because I would like to do some advertisement but because I thing the talk given by Stefan Roock about "Simplicity in Software Projects" (held at the german XP-Days this year in Karlsruhe) is absolutely excellent. If you are able to understand spoken german you should definitely take the time (about 60min) and listen to Stefans talk (screencast or pure mp3). It is funny, entertaining and inspiring for every day project life. The sound quality is somewhat poor but the talk is definitely worth listen to anyway.

In general I don't like to write too positive about things that happens within my company. This often sounds like pure advertisement for the company business and therefore I don't like it for my private blog. But today I need to make an exception. Not because I would like to do some advertisement but because I thing the talk given by Stefan Roock about "Simplicity in Software Projects" (held at the german XP-Days this year in Karlsruhe) is absolutely excellent. If you are able to understand spoken german you should definitely take the time (about 60min) and listen to Stefans talk (screencast or pure mp3). It is funny, entertaining and inspiring for every day project life. The sound quality is somewhat poor but the talk is definitely worth listen to anyway.

Excellent Talk about Simplicity

OSGi and IntelliJ IDEA

Today my collegue Robert Beeger told me that he is working on a plugin for the IntelliJ IDEA development environment to support the OSGi programming model. And the first initial release of Osmorc (that is the name of the plugin project) is already available for download. I haven't tried it myself (I am using Eclipse for bundle development) but it sounds quite promising from his announcement. The support seems to be somewhat limited for this very early release but it is great to see that support for OSGi is becoming reality for more IDEs than just Eclipse.

Today my collegue Robert Beeger told me that he is working on a plugin for the IntelliJ IDEA development environment to support the OSGi programming model. And the first initial release of Osmorc (that is the name of the plugin project) is already available for download. I haven't tried it myself (I am using Eclipse for bundle development) but it sounds quite promising from his announcement. The support seems to be somewhat limited for this very early release but it is great to see that support for OSGi is becoming reality for more IDEs than just Eclipse.

OSGi and IntelliJ IDEA

Slides from WJAX

Finally I uploaded all my slides from the WJAX conference this year to the events section. In addition to the slide PDFs I would like to point to the demo and code material that Gerd Wütherich put online for our Spring and OSGi session. The zip file contains all the source code of the examples from the talk as well as ready-to-use target platforms for the examples, including Equinox 3.3 and Spring Dynamic Modules RC1 as a PDE target platform. Very nice package if you would like to get started with Spring-DM.

Finally I uploaded all my slides from the WJAX conference this year to the events section. In addition to the slide PDFs I would like to point to the demo and code material that Gerd Wütherich put online for our Spring and OSGi session. The zip file contains all the source code of the examples from the talk as well as ready-to-use target platforms for the examples, including Equinox 3.3 and Spring Dynamic Modules RC1 as a PDE target platform. Very nice package if you would like to get started with Spring-DM.

Slides from WJAX

13949712720901ForOSX

Even though I am a big fan of ThinkPad notebooks I like Apples Mac OS X and their notebook hardware a lot. I am just waiting for the day that they integrate a trackpoint into their keyboard design... ;-) Unfortunately they seem to reduce their effort to keep up to date with their Java implementation for OS X. There is still no Java 6 for OS X and there are no signs for it on the horizon. Therefore I vote for it via this blog post. See more details about this campaign.

Even though I am a big fan of ThinkPad notebooks I like Apples Mac OS X and their notebook hardware a lot. I am just waiting for the day that they integrate a trackpoint into their keyboard design... ;-) Unfortunately they seem to reduce their effort to keep up to date with their Java implementation for OS X. There is still no Java 6 for OS X and there are no signs for it on the horizon. Therefore I vote for it via this blog post. See more details about this campaign.

13949712720901ForOSX

Mentioned on refactoring.com :-)

It happened during mid August but I realized it during the past days: Martin Fowler mentioned the refactoring podcast episodes (1 and 2) that I recorded together with Eberhard Wolff for Software Engineering Radio on www.refactoring.com. Its just a short note on the site but for me it sounds quite positive... :-)

It happened during mid August but I realized it during the past days: Martin Fowler mentioned the refactoring podcast episodes (1 and 2) that I recorded together with Eberhard Wolff for Software Engineering Radio on www.refactoring.com. Its just a short note on the site but for me it sounds quite positive... :-)

Mentioned on refactoring.com :-)

Experiences from following "The Eclipse Way" at OOP 2008

Together with my colleague Ivo Eitner from the Aspecta/HDI-Gerling Lebensversicherung I will give a talk at the upcoming OOP conference in Munich. The conference is from January 21st to the 25th and we are going to talk about our experiences from using and adapting "The Eclipse Way" - the agile software development process that is used by the Eclipse SDK team. We have adopted quite a number of their practices over the past three years within a larger development project in the insurance domain and we will present our experiences using those practices. Here is the german abstract of this talk.

Together with my colleague Ivo Eitner from the Aspecta/HDI-Gerling Lebensversicherung I will give a talk at the upcoming OOP conference in Munich. The conference is from January 21st to the 25th and we are going to talk about our experiences from using and adapting "The Eclipse Way" - the agile software development process that is used by the Eclipse SDK team. We have adopted quite a number of their practices over the past three years within a larger development project in the insurance domain and we will present our experiences using those practices. Here is the german abstract of this talk.

Experiences from following "The Eclipse Way" at OOP 2008

Article on Aspect-Weaving for OSGi

The latest german Eclipse-Magazin contains an article that I wrote together with Peter Friese (from Gentleware) and Heiko Seeberger (from Metafinanz) about using AOP for Eclipse RCP applications. The article describes how load-time aspect weaving can be used for real-world OSGi-based applications. Within the article we describe how security-related issues can be implemented using AOP and how those aspects can be woven into an RCP app using AJEER or the Equinox Aspects load-time weaving support for OSGi. The complete article can be found in the publications section.

The latest german Eclipse-Magazin contains an article that I wrote together with Peter Friese (from Gentleware) and Heiko Seeberger (from Metafinanz) about using AOP for Eclipse RCP applications. The article describes how load-time aspect weaving can be used for real-world OSGi-based applications. Within the article we describe how security-related issues can be implemented using AOP and how those aspects can be woven into an RCP app using AJEER or the Equinox Aspects load-time weaving support for OSGi. The complete article can be found in the publications section.

Article on Aspect-Weaving for OSGi

Ranking from Java-Forum-Stuttgart

The presentation ranking from the Java-Forum-Stuttgart 2007 is now online. And I am a little bit proud to see that I am among the top ten presentations - the forth year in a row. Wow... :-)

The presentation ranking from the Java-Forum-Stuttgart 2007 is now online. And I am a little bit proud to see that I am among the top ten presentations - the forth year in a row. Wow... :-)

Ranking from Java-Forum-Stuttgart

Pictures from SpringOne

I was quite surprised finding a picture of myself on the SpringOne website. It was shot during the "Spring and Eclipse RCP" session, I think... And look here for some other pictures from SpringOne.

I was quite surprised finding a picture of myself on the SpringOne website. It was shot during the "Spring and Eclipse RCP" session, I think... And look here for some other pictures from SpringOne.

Pictures from SpringOne

Slides from Java-Forum-Stuttgart

Yesterday I was at the Java-Forum-Stuttgart, a one-day conference organized by the Java User Group of Stuttgart. Together with Bernd Kolb and Gerd Wütherich I gave a talk about the combination of Spring and OSGi. You can download the slides, if you like.

Yesterday I was at the Java-Forum-Stuttgart, a one-day conference organized by the Java User Group of Stuttgart. Together with Bernd Kolb and Gerd Wütherich I gave a talk about the combination of Spring and OSGi. You can download the slides, if you like.

Slides from Java-Forum-Stuttgart

Slides and examples from SpringOne 2007

Here are the slides from my SpringOne sessions as PDF files: Spring and Eclipse RCP, Hands-On Spring-OSGi. The example that I showed during the Eclipse-RCP talk containing the example RCP application frond-end based on Spring-OSGi that communicates with the Spring-OSGi-based backend service running inside a Jetty server is also available for download. Here are the two example projects. You can use them together with the pre-defined workspace that I used during the hands-on session.

Here are the slides from my SpringOne sessions as PDF files: Spring and Eclipse RCP, Hands-On Spring-OSGi. The example that I showed during the Eclipse-RCP talk containing the example RCP application frond-end based on Spring-OSGi that communicates with the Spring-OSGi-based backend service running inside a Jetty server is also available for download. Here are the two example projects. You can use them together with the pre-defined workspace that I used during the hands-on session.

Slides and examples from SpringOne 2007

Resources for Hands-On-Spring-OSGi session

For my session at SpringOne "Hands-On Spring-OSGi" I created a ready-to-use workspace for playing with Spring-OSGi. This workspace (zip, 40MB) is based on the example by Bernd Kolb (many thanks to Bernd for this example which is really great). Some setup instructions can be found in the slides for the session (PDF).

For my session at SpringOne "Hands-On Spring-OSGi" I created a ready-to-use workspace for playing with Spring-OSGi. This workspace (zip, 40MB) is based on the example by Bernd Kolb (many thanks to Bernd for this example which is really great). Some setup instructions can be found in the slides for the session (PDF).

Resources for Hands-On-Spring-OSGi session

Arrived at SpringOne 2007

Today I arrived at the SpringOne conference in Antwerpen, Belgium. The conference takes place in the Metropolis Business Center (the same spot as the JavaPolis takes place). This is the first time for me to attend and speak at a conference taking place in this location. Therefore I was pretty impressed by the location which basically is a huge cinema complex. The sessions are held in cinema rooms. I never had such a huge projection area... :-) The sounds seems to be pretty good as well since the THX logo is above every entry. Very very cool, especially for an old Lucasfilm and THX fan like me. And last but not least: it slightly smells of popcorn all over the place... :-)

Today I arrived at the SpringOne conference in Antwerpen, Belgium. The conference takes place in the Metropolis Business Center (the same spot as the JavaPolis takes place). This is the first time for me to attend and speak at a conference taking place in this location. Therefore I was pretty impressed by the location which basically is a huge cinema complex. The sessions are held in cinema rooms. I never had such a huge projection area... :-) The sounds seems to be pretty good as well since the THX logo is above every entry. Very very cool, especially for an old Lucasfilm and THX fan like me. And last but not least: it slightly smells of popcorn all over the place... :-)

Arrived at SpringOne 2007

Refactoring Pt. 2 at Software Engineering Radio

A few days ago the second episode on refactoring was published at se-radio.net. In this podcast episode I talk with Eberhard Wolff about some more complicated refactoring situations, for example larger refactorings, refactorings for published APIs and refactorings that affect the database schema or the database access code.

A few days ago the second episode on refactoring was published at se-radio.net. In this podcast episode I talk with Eberhard Wolff about some more complicated refactoring situations, for example larger refactorings, refactorings for published APIs and refactorings that affect the database schema or the database access code.

Refactoring Pt. 2 at Software Engineering Radio

Spring, Eclipse, and OSGi at SpringOne 2007

If you would like to know more about Spring, OSGi and the usage of both technologies together you should think about going to SpringOne 2007. The SpringOne conference is organized by the Belgium Java User Group and Interface21 and takes place from June 20 to June 22 in Antwerp. The conference is focussed on Spring and covers a lot of different topics. And there are three sessions touching the Spring-OSGi combination:

• Adrian Colyer and Costin Lean: OSGi, a New Foundation for Enterprise Apps
• Martin Lippert: Spring and Eclipse RCP
• Martin Lippert: Hands-On Spring-OSGi

So don't miss it!!!

If you would like to know more about Spring, OSGi and the usage of both technologies together you should think about going to SpringOne 2007. The SpringOne conference is organized by the Belgium Java User Group and Interface21 and takes place from June 20 to June 22 in Antwerp. The conference is focussed on Spring and covers a lot of different topics. And there are three sessions touching the Spring-OSGi combination:

• Adrian Colyer and Costin Lean: OSGi, a New Foundation for Enterprise Apps
• Martin Lippert: Spring and Eclipse RCP
• Martin Lippert: Hands-On Spring-OSGi

So don't miss it!!!

Spring, Eclipse, and OSGi at SpringOne 2007

Second milestone of Spring-OSGi released

Past Friday Costin Leau announced the second milestone build of the Spring-OSGi project. This is an update to the M1 release and fixes some compatibility issues. Aside from some maven build stuff and improved OSGi manifest definitions there seems to be nothing really new in there. The explicit support for web apps is still missing... :-(

But my colleague Bernd Kolb told me that he succeeded in setting up the pet shop example via OSGi with just a few hacks, getting the Spring-OSGi stuff to work nicely within the web app using Equinox and the embedded jetty. I hope his code will be public available soon so that everybody can see how easy and nice it is to implement client-server and web applications using OSGi and Spring together. :-)

Past Friday Costin Leau announced the second milestone build of the Spring-OSGi project. This is an update to the M1 release and fixes some compatibility issues. Aside from some maven build stuff and improved OSGi manifest definitions there seems to be nothing really new in there. The explicit support for web apps is still missing... :-(

But my colleague Bernd Kolb told me that he succeeded in setting up the pet shop example via OSGi with just a few hacks, getting the Spring-OSGi stuff to work nicely within the web app using Equinox and the embedded jetty. I hope his code will be public available soon so that everybody can see how easy and nice it is to implement client-server and web applications using OSGi and Spring together. :-)

Second milestone of Spring-OSGi released

Slides from the Turkish Eclipse Summit talk online

Finally I found the time to upload my slides from the Turkish Eclipse Summit. You can find them in the events section, as usual.

The event was well organized and it was fun giving a talk there. Many many thanks again to Naci Dai for inviting me to this great event and to Karen Dai for all their help. If you would like to see some pictures from Istanbul (where the summit took place) you should go to Mike Milinkovichs Flickr pictures from Istanbul.

Finally I found the time to upload my slides from the Turkish Eclipse Summit. You can find them in the events section, as usual.

The event was well organized and it was fun giving a talk there. Many many thanks again to Naci Dai for inviting me to this great event and to Karen Dai for all their help. If you would like to see some pictures from Istanbul (where the summit took place) you should go to Mike Milinkovichs Flickr pictures from Istanbul.

Slides from the Turkish Eclipse Summit talk online

JAX session slides online

While sitting the last day at the German JAX conference I put all my session slide material online. You can find all slides in the events section.
My company recorded the session about how the practices of the Eclipse team process could be adopted for in-house projects and put an online screencast on their website. So if you would like to listen to that talk feel free to watch the screencast.

While sitting the last day at the German JAX conference I put all my session slide material online. You can find all slides in the events section.
My company recorded the session about how the practices of the Eclipse team process could be adopted for in-house projects and put an online screencast on their website. So if you would like to listen to that talk feel free to watch the screencast.

JAX session slides online

First milestone of Spring-OSGi released

Costin Leau from the team at Interface21 announced the availability of the first milestone of the Spring-OSGi integration. If you haven't already you should definitely look at this new Spring sub-project. Many people (including myself ;-) consider this integration as the next big step for the Spring framework. Unfortunately the support for building web applications is currently broken and therefore not part of this milestone release.

Costin Leau from the team at Interface21 announced the availability of the first milestone of the Spring-OSGi integration. If you haven't already you should definitely look at this new Spring sub-project. Many people (including myself ;-) consider this integration as the next big step for the Spring framework. Unfortunately the support for building web applications is currently broken and therefore not part of this milestone release.

First milestone of Spring-OSGi released

Invited Talk at the Turkish Eclipse Summit 2007

I am invited to the Turkish Eclipse Summit 2007 that takes place in Istanbul at the 30th of April this year. I will talk about OSGi and the Eclipse Equinox OSGi implementation. The talk will explain my basic understanding of what the OSGi runtime is, where it can be used for, and what the benefits of using it as a basic infrastructure for all kind of applications are. And because I am somehow involved in the Equinox Incubator project I will, of course, talk a little bit about some cool stuff that you can do with the Equinox implementation like the Spring integration, AOP load-time weaving and stuff like that... :-)

I am invited to the Turkish Eclipse Summit 2007 that takes place in Istanbul at the 30th of April this year. I will talk about OSGi and the Eclipse Equinox OSGi implementation. The talk will explain my basic understanding of what the OSGi runtime is, where it can be used for, and what the benefits of using it as a basic infrastructure for all kind of applications are. And because I am somehow involved in the Equinox Incubator project I will, of course, talk a little bit about some cool stuff that you can do with the Equinox implementation like the Spring integration, AOP load-time weaving and stuff like that... :-)

Invited Talk at the Turkish Eclipse Summit 2007

What a nice book review

The Miami Java Users Group posted a nice review of the book about large and complex refactorings that Stefan Roock and I wrote. Isn't it great to read such positive feedback? :-)

The Miami Java Users Group posted a nice review of the book about large and complex refactorings that Stefan Roock and I wrote. Isn't it great to read such positive feedback? :-)

What a nice book review

Don't forget to meet at JAX 2007

The next conference that I am speaking at is approaching fast. At the JAX 2007 in Wiesbaden, Germany, I am going to talk about Spring and OSGi and why this combination is so promising, I think. Will be fun to present this together with Gerd Wütherich and Bernd Kolb at the Spring Day of the conference on Monday.
On Tuesday I have two sessions together with Tobias Widmer from the IBM team in Zurich that works on Eclipse. We will talk about "The Eclipse Way", the agile development process behind the Eclipse team (this will be the first session). The second session will cover the question how this process can be adapted (and adopted) for typical in-house and non-open-source projects where developers are not building tools for themselves.
Last but not least the session on Wednesday is together with my former colleague Gernot Neppert. We are going to talk about our experiences from building a large-scale system for an insurance company that is heavily build on OSGi and is especially using the Eclipse Extension Registry to create a really flexible and extensible architecture.

The next conference that I am speaking at is approaching fast. At the JAX 2007 in Wiesbaden, Germany, I am going to talk about Spring and OSGi and why this combination is so promising, I think. Will be fun to present this together with Gerd Wütherich and Bernd Kolb at the Spring Day of the conference on Monday.
On Tuesday I have two sessions together with Tobias Widmer from the IBM team in Zurich that works on Eclipse. We will talk about "The Eclipse Way", the agile development process behind the Eclipse team (this will be the first session). The second session will cover the question how this process can be adapted (and adopted) for typical in-house and non-open-source projects where developers are not building tools for themselves.
Last but not least the session on Wednesday is together with my former colleague Gernot Neppert. We are going to talk about our experiences from building a large-scale system for an insurance company that is heavily build on OSGi and is especially using the Eclipse Extension Registry to create a really flexible and extensible architecture.

Don't forget to meet at JAX 2007

Spring and OSGi at EclipseCon

Yesterday I gave a tutorial about Spring and OSGi together with BJ Hargrave at EclipseCon 2007. It was a short tutorial, just 2 hours, fully packed with a lot of demo material. BJ did a great job of preparing some examples for it.
If you didn't have the chance to participate in the tutorial you can download the slides as well as the source code for all the examples here. The zip file contains a team project set which you can easily import into your Eclipse workspace. More detailed information on installing and running the examples can be found in the slides.

Yesterday I gave a tutorial about Spring and OSGi together with BJ Hargrave at EclipseCon 2007. It was a short tutorial, just 2 hours, fully packed with a lot of demo material. BJ did a great job of preparing some examples for it.
If you didn't have the chance to participate in the tutorial you can download the slides as well as the source code for all the examples here. The zip file contains a team project set which you can easily import into your Eclipse workspace. More detailed information on installing and running the examples can be found in the slides.

Spring and OSGi at EclipseCon

Refactoring Pt. 1 at Software Engineering Radio

Last friday the first episode on refactoring was published at se-radio.net. In this podcast episode I talk with Eberhard Wolff about the general ideas and concepts of refactoring. This is the first episode that I am involved in and I hope the feedback will be somewhat positive... :-)

Last friday the first episode on refactoring was published at se-radio.net. In this podcast episode I talk with Eberhard Wolff about the general ideas and concepts of refactoring. This is the first episode that I am involved in and I hope the feedback will be somewhat positive... :-)

Refactoring Pt. 1 at Software Engineering Radio

XP 2007 Call for Papers

This years european conference on Extreme Programming and Agile Software Development, the XP 2007, takes place in Como, Italy. Again I am member of the program committee and I would like to invite you to submit papers, tutorials, workshop proposals and so on. The CfP is still open, so don't forget to submit something!!!

This years european conference on Extreme Programming and Agile Software Development, the XP 2007, takes place in Como, Italy. Again I am member of the program committee and I would like to invite you to submit papers, tutorials, workshop proposals and so on. The CfP is still open, so don't forget to submit something!!!

XP 2007 Call for Papers

Three Secrets... ;-)

Thanks to Eberhard I have to tell you three things about myself before I am supposed to hand over the baton to some of my colleagues and friends...

• I started my programming carreer with the Amstrad/Schneider CPC 664, the second edition of this home computer that was the first one with an integrated a floppy disk drive (strange 3" format). After a few years a got a mouse for this machine and wrote a completely useless icon editor for fun (in basic, of course). I thought icons would be a cool thing to edit... :-)
  
• I am one of the authors of Discovery DTP, a full-featured desktop publishing system that I implemented for the Atari ST/TT, together with a friend of mine. The program was published as shareware by the ST-Computer magazine, a german computer magazine for Atari at that time. This was implemented in C and we worked on it for several years. And, of course, we implemented everything on our own, including virtual memory management, vector-font rendering, text formatting and much more... I still have the source code on a CD. Fun to read... I think I made every single mistake that my software engineering professor at the University talked about years later when I started to study computer science.
  
• My first (and last) computer game that I played intensively was Sorcery, a really strange fantasy game for the Amstrad/Schneider CPC 664. I found a screenshot of that game, looks really cool...
  

And now, the next three people in the row: congratulations to Sebastian, Robert and Stefan.

Thanks to Eberhard I have to tell you three things about myself before I am supposed to hand over the baton to some of my colleagues and friends...

• I started my programming carreer with the Amstrad/Schneider CPC 664, the second edition of this home computer that was the first one with an integrated a floppy disk drive (strange 3" format). After a few years a got a mouse for this machine and wrote a completely useless icon editor for fun (in basic, of course). I thought icons would be a cool thing to edit... :-)
  
• I am one of the authors of Discovery DTP, a full-featured desktop publishing system that I implemented for the Atari ST/TT, together with a friend of mine. The program was published as shareware by the ST-Computer magazine, a german computer magazine for Atari at that time. This was implemented in C and we worked on it for several years. And, of course, we implemented everything on our own, including virtual memory management, vector-font rendering, text formatting and much more... I still have the source code on a CD. Fun to read... I think I made every single mistake that my software engineering professor at the University talked about years later when I started to study computer science.
  
• My first (and last) computer game that I played intensively was Sorcery, a really strange fantasy game for the Amstrad/Schneider CPC 664. I found a screenshot of that game, looks really cool...
  

And now, the next three people in the row: congratulations to Sebastian, Robert and Stefan.

Three Secrets... ;-)

Labels and Specialized Feeds

I recently switched to the new blogger implementation. Now I am able to tag my posts with self-defined labels and you are able to watch blog entries per label or even subscribe to atom or rss feeds per label. Here are a few example feed URLs for my blog:

• The complete atom feed
• The complete rss feed
• The atom feed for the label "Eclipse"
• The atom feed for the label "Spring"

Oh, btw: Happy New Year!

I recently switched to the new blogger implementation. Now I am able to tag my posts with self-defined labels and you are able to watch blog entries per label or even subscribe to atom or rss feeds per label. Here are a few example feed URLs for my blog:

• The complete atom feed
• The complete rss feed
• The atom feed for the label "Eclipse"
• The atom feed for the label "Spring"

Oh, btw: Happy New Year!

Labels and Specialized Feeds