K-Meleon itself and most of the plugins compiled without any major problem (not counting adding some include path or something like that).
I should point out that I'm using MSVC9, so it's probably the reason for lot of the following problems:
Bookmarks plugin does not compile, because it has string type mismatches almost everywhere (88 errors total). I din't look more into it yet, there are two more bookmarks plugins available to use.
Macros2 has minor problems because of more strict compiler.
I can't compile JSBridge. At first there were problems with some macros in nsGenericFactory.cpp, probably something from older Mozilla code, I couldn't find them in current source. I changed the file according to the one with the same name in K-Meleon's main directory, so compiler is now happy, but linker somehow managed to find three unresolved external symbols. They seem to be existing functions, but with wrong type parameters (if I correctly understand how the identifiers are created). I'm currently trying to find where it got messed up.
Other than that, things seem to work.
Exiting problem is present. If I just start the browser and close it, then it's ok. But if I do something first, like open few pages, then it does not work correctly.