||Enable threading support through pthread (or other libraries on AIX, IRIX, HPUX, Solars). Highly recommended
||Enable POSIX threads. Highly recommended, otherwise both build and run-time features may not work properly.
||Use separate thread to init connection (unsafe)
||Controls whether to build the Abyss web-server with pthreads or fork 'threading'.
||Add elisp threading support
||Enable support for green threads