Frameserver is a plugin for video editing apps to do FrameServing, Image Sequence export and AudioServing.
Frameserving and Audioserving are the techniques used to transfer audio/video data from one application to another without doing a full fledged render and temporary files. Frameserver is a plugin for NLEs enabling them to export their timeline audio/video data outside so that other applications can use the timeline directly as input.
Another use of the Frameserver is to serve audio/video data to an application that does not understand the source format. If you have a video editor that can open .MOV files and your MPEG encoder can read only .AVI input files, you can open the .MOV file in your NLE and use Frameserver to serve the a/v data to your MPEG encoder. This increases compatibility between applications.
Frameserver can also export the video from your NLE as an Image sequence. Frames can be saved in lossless BMP, TIFF, PNG and high quality JPEG formats.
Frameserver's build uses the SCons build system (you can find the build configs in the files SConstruct and SConscript throughout the codebase). Most of the executables get built using MS Visual Studio 6.0 and some of the newer binaries require MS Visual Studio 2008.
Frameserver works as a plug-in for various video editing 'host' applications and allows exporting the rendered video from them as .avi files. To build the plug-in for each host application, you need to have the host's plug-in SDK. You need to download each plug-in SDK yourself from the host application's website, because their Terms & Conditions do not allow redistributing them with the Frameserver codebase.
Once downloaded, place the host SDK files in the following hierarchy:
src/SDKs
+-- Premiere
| +-- compiler
| +-- cs4
| +-- cs5
+-- VegasV2
| +-- libFileIO
+-- Wax