Yes, FreeBSD supports System V-style IPC. This includes shared memory, messages and semaphores. You need to add the following lines to your kernel config to enable them.
options SYSVSHM # enable shared memory options SYSVSEM # enable for semaphores options SYSVMSG # enable for messaging
Note: In FreeBSD 3.2 and later, these options are already part of the GENERIC kernel, which means they should already be compiled into your system.
Recompile and install your kernel.