I would like to see IrfanView on my portableapps. It's a small but a very functional viewer/edior for pictures, but also a movie/mp3 player... and yes, it is a freeware but I don't know if it has an open source???
The web site is http://www.irfanview.com/
Some IrfanView features:
* Many supported file formats (click here the list of formats)
* Multi language support
* Thumbnail/preview option
* Slideshow (save slideshow as EXE/SCR or burn it to CD)
* Show EXIF/IPTC/Comment text in Slideshow/Fullscreen etc.
* Support for Adobe Photoshop Filters
* Fast directory view (moving through directory)
* Batch conversion (with image processing)
* Multipage TIF editing
* File search
* Email option
* Multimedia player
* Print option
* Change color depth
* Scan (batch scan) support
* IPTC editing
* Effects (Sharpen, Blur, Adobe 8BF, Filter Factory, Filters Unlimited, etc.)
* Extract icons from EXE/DLL/ICLs
* Lossless JPG rotation
* Many hotkeys
* Many command line options
* Many PlugIns
* Only one EXE-File, no DLLs, no Shareware messages like "I Agree" or "Evaluation expired"
* No registry changes without user action/permission!
* and much much more