What other tools are available for bidirectional mirroring of CVS repositories?
It is not possible to mirror CVS repositories bidirectionally without special provisions for protection and uniqueness of elements. There is a project called DCVS (Distributed Concurrent Versions System) which consists of modified and extended versions of CVS and CVSup that enable you to synchronize a network of DCVS servers with dedicated lines of development. DCVS is available in source and binary packages for several platforms from elego Software Solutions GmbH, Berlin. You can also download DCVS via CVSup or read an overview of DCVS. There is also a commercial tool from WANdisco called CVS Replicator which offers N-way replication of CVS repositories among multiple sites.