apache2-mpm-prefork 2.0.55-4ubuntu2.3 (ia64 binary) in ubuntu dapper

 This Multi-Processing Module (MPM) implements a non-threaded,
 pre-forking web server that handles requests in a manner similar to
 Apache 1.3. It is appropriate for sites that need to avoid threading for
 compatibility with non-thread-safe libraries. It is also the best MPM
 for isolating each request, so that a problem with a single request will
 not affect any other.
 .
 It is not as fast, but is considered to be more stable.