BitKeeper is a fast, enterprise-ready, distributed SCM that scales
up to very large projects and down to tiny ones.
Features
 * Simple: An easy to use command line interface.
 * Scalable: Nested Repositories are submodules done right! Version
	control collections of repositories.
 * Flexible: Hybrid mode for binary files that uses a cloud of server for
	binaries instead of bloating the source repositories.
 * Accurate: Tracking of file operations like creates, deletes, and renames.
 * Safe: All file accesses validate checksums for integrity. All file
	writes include redundancy for error correction.
 * Dependable: Highly accurate auto-merge that uses the whole history to
	resolve conflicts. Most other systems use variations of diff3.
 * Discernable: Source annotations instantly available.
 * Fast: High performance and scales to very large repositories.
 * Free: Licensed under the Apache Version 2 license

WWW: http://www.bitkeeper.org/