I had previously talked about adding a protocol to Instantbird, that focused on adding SIPE (Microsoft Office Communicator support). Since then I've been slowly working on defeating SIPE. Fortunately I found a few flags that help us compile it easily in Instantbird: we can declare that we do not have gmime and the standard libpurple MIME functions will be used (they might not be as good, but it keeps from adding >10 MB of source to Instantbird).
Some modifications to the SIPE source were made to compile it in Instantbird (note that most of the changes were probably more based on using MSVC, than having to do with Instantbird). The code is also broken up into a few different sections the core, api, and purple are ones we care about (they're working on making a general Office Communicator protocol library, so the purple folder contains the libpurple bindings that use the api, while the core is private).
Changes to purple consisted mostly of ifdefs that remove some header files not supported on Windows. For example, I encountered a few of:
Luckily there was already a define HAVE_UNISTD_H, so I just needed to add:
Easy! There were also a couple other issues, but those were rather trivial.
There isn't a specific issue in the core I'd like to highlight, it did use a few glib functions which we didn't have (we removed the files, as they were unused), they were all reimplemented in libpurple though, so we were able to just define the function calls to the libpurple variants.
This had similar issues the core (in particular, there was a function which used g_usleep, which is blocking and a definite no-no for a protocol plug-in, I've removed that...hopefully it doesn't break anything!) In addition to that, we needed to use the libpurple l10n system instead of glib's gi18n.h, this was easily copied from libpurple's internal API though.
So at this point...I have a copy of SIPE compiled! Unfortunately since I'm using Visual Studio Express I cannot compile on my computer and deploy to other computers for testing (a Mozilla issue with how it uses some of the header files, etc., I believe). I'm looking into trying to get this to work though, apparently using the exact same copy of MSVC Redistributable might help. Once this is tested, hopefully it'll land in Instantbird for use!
Unrelated to SIPE, but recently I landed a patch in Instantbird to add back Sametime support (Sametime is Lotus Notes' equivalent to Office Communicator). You can see the gory details in bug 102, but in general it's similar to what I've (not gone into great detail about) here. Most of getting Sametime to work was rewriting some C code that doesn't compile in MSVC. There's also a diff of all the changes I made to the libpurple Sametime plugin and the external library (called Meanwhile) to get it to work. Once I get Monotone (a version control system) set up I'll look into getting these changes pushed back to libpurple to avoid diverging code bases.