BitKeeper is the original distributed source management system. Now available as Open Source under the Apache 2.0 License.
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
 
Clone a project and push changes
    
$ bk clone bk://bkbits.net/bkdemo/bk_demo
$ cd bkdemo
# edit files using your favorite editor
$ bk -Ux new
$ bk commit -y"Comments"
$ bk push
    
  
  Create a project and commit
    
$ bk init new_project
$ cd new_project
# edit files using your favorite editor
$ bk -Ux new
$ bk commit -y"Initial commit"