Home:Professional:Version Control

This page summarizes essential differences between some version control systems I have experience with. Check marks “✓” indicate ‘yes’, dashes “&ndash” indicate ‘no’. An empty cell indicates ‘unknown’. Separate lines within a cell usually indicate options.

Architecture

Version Control Architectures
Name	Open Source	Platform	Server- Based [2]	Repository	Access Model	Access Method	Metadata
Projector	–	MacOS	no	proprietary	command line [3]	file system	–
SourceSafe	–	M$	yes	proprietary	GUI	file system
VOODOO	–	MacOS	yes	proprietary	IDE [1]	Apple Events	–
RCS	✓	open	no	RCS	command line	file system	–
CVS	✓	open	no	RCS	command line [4]	file system	–
Subversion	✓	open	no yes	Berkeley DB	command line [4]	file system WebDAV/HTTP WebDAV/HTTPS SVN SVN/SSH	✓
ClearCase	–	UNIX W$	yes	proprietary (Versioned OBject)	client command line	file system virtual file system

[1] Working operations through the version control support in the CodeWarrior IDE. Administrative functions through a client.

[2] This indicates only whether the source control system itself provides a server, not whether it relies on the underlying services of a file server, for example.

[3] All operations through the Macintosh Programmer's Workshop (MPW) IDE.

[4] While the primary access is by means of a command line, secondary third-party graphical user interfaces are available.

Model

Version Control Models
Name	Locking	Multiple Check-Outs	Atomic Check-in	Track Moved Files	Revision Granularity	Dimensionality
Projector				–
SourceSafe	exclusive	–	–	–
VOODOO	exclusive	–	–	–
RCS				–	file	1
CVS	shared	✓	–	–	file	3
Subversion	shared	✓	✓	✓	hierarchy	2
ClearCase			–	✓

Discussion

Projector

Original version control system for the Macintosh Programmer's Workshop (MPW) IDE.

VOODOO

Server and plug-in for the Metrowerks CodeWarrior IDE on MacOS.

CVS

Each file has its own revision and branching history. Although there are no true project revisions, they can be approximated by tagging selected sets of file revisions. Directories constitute just a default set of files.

Subversion

Access to the repository is essentially through an in-process data base, but version control servers may be built on top of this. A revision is a snapshot of the entire file hierarchy. Although there are no true branches, they may be approximated by making copies of project folders.