OOoServer
The OpenOffice.org server manages a pool of OpenOffice.org processes. It makes sure that only one connection at the time can be made to a particular process. The level of concurrency can be configured through the process pool size. By default each connection is handled by a new OpenOffice.org process, but it is possible to configure a life span, which results in the reuse of processes.
OOoServer is hosted on SourceForge.
Comments and bug reports are welcome at support@re.be.