This page contains a list of gotchas that have snagged new and experienced plug-in devs, so that you may not get snagged by them too:
<Jeff R says: Is there already something like this in the wiki that I missed? I can't believe I'd be the first to wiki this!>
- OS X compiling should be done to a dylib (Dynamic Library), and is NOT linked against a provided library. This is counterintuitive to most developers who are used to adding libraries/frameworks into their Xcode projects in order to link against them. You only need to include the header files themselves.
- Advanced On OS X 10.5 Leopard, if you get a strange compile error related to missing libraries of a given architecture, chances are you have a custom version of the library installed in /usr/local/lib and it is overriding the one that comes with OS X. Unfortunately the only known solutions thus far is to remove the library from /usr/local/lib, as the OS's SDKs automatically include /usr/local/lib in the library search path.
- If you use the version 2 headers and want to compile version 2 code, you must define XPLM200. Otherwise it will limit you to version 1 functionality in order to be backwards compatible to versions of X-Plane older than v9.