@unknownuser said:
Extend The GIMP's functionality with scripts and Photoshop-plugins
You can extend The GIMP's functionality even more by adding scripts (Script-Fu) or Photoshop-filters to your GIMP-installation. A good resource for GIMP-scripts an tutorials is the GIMP User Group website.
For using Photoshop-plugins in GIMP the pspi.exe plugin http://www.gimp.org/~tml/gimp/win32/gimp-pspi-1.0.3.zip for Windows has been created. you install this by extracting it to your GIMP installation directory (it will place itself to the lib/gimp/2.0/plug-ins folder). After a restart of GIMP the Xtns-menu of GIMP's main window got a new item called Photoshop Plug-in Settings. When you click on it you can set a path to where your Photoshop-plugins are stored. GIMP will load the filters that are found in that folder at startup. These filters are added to GIMP's Filters menu.
You can find free Photoshop-filters at FreePhotoshop.com. The Virtual Photographer-plugin is good to begin with. Not all Photoshop-plugins work with GIMP, so you should try using some of them to see whether they work fine.
@unknownuser said:
Seamless Workshop plug-in - Seamless Workshop is a freeware Adobe Photoshop compatible plug-in filter. It composes seamless tile from any image. Also, a "surrealistic modification" of a picture can be produced. It is a powerful tool for texture creators, and a helpful toy for graphic designers. An advanced tileable algorithm is used. The unique 'Seamless Blur' effect can be useful for any available tileable pattern
http://www.redfieldplugins.com/SeamlessWorkshop.exe
Tested and worked flawlessly in Gimp.