Another question related to PC build.
Where can I find the sources for this one, and how to build it?
The bad news is that you are setting up yourself for a lot of work if you want to build all the dependencies from scratch. The good news is that it can be done though. Be aware that most of the Win32 dependencies require modifications specifically for supporting Oolite anyway. The modified SDL.dll sources are already included in the trunk's cross platform deps folder and the modifications required for libespeak.dll are also included. For the rest, you will have to get the sources yourself and make sure you download the versions used in Oolite, because there are no guarantees whatsoever that newer library versions will work.
Be sure to read the document titled ExternalLibrariesSourceCodeChanges.txt, located in the Doc folder before you begin. Start with the basics: zlib1.dll, SDL.dll, libogg/libvorbis + SDL_mixer.dll, libpng14.dll. I know that there will be lots of questions, so feel free to take it to PM if you get stuck. I will try to help as much as I can.
Regarding the js32ECMAv5.dll, this is the source of the Spidermonkey library for Firefox 4. Building this is a b!tch of a task. I will probably have to send you ready-made makefiles for it, because the official Spidermonkey build does not support our toolchain (GCC/MinGW) and yet another special build had to be made for it.
Another one of the bad ones is gnustep-base-1_20.dll, but leave that till very last. It has extensive modifications to the Objective-C library itself.