Help TOC > DEXlib
DEXlib Date: 2008/03/04 12:11:08
Revision: 1.9



Why DEXlib (and STEPmod)?

DEXlib and STEPmod

See the CVS access guide for information on how to get hold of STEPmod and DEXlib.
Alternatively, you can visit the PLCS resources web site (

Note - Both DEXlib and STEPmod are implemented in XML and uses XSL and JScripts. It is therefore necessary to use Internet Explorer version 6 or later to view these sites.


The DEX library is owned and operated by OASIS Product Life Cycle Support TC. Further information on this Technical Committee, and other OASIS initiatives, can be found at (, and in the OASIS section of these information pages.


STEPmod is an abbreviation for 'the STEP modules repository'. It is the development environment for all ISO 10303 STEP modules. A local copy of STEPmod must be located alongside the STEPmod repository, within a common parent directory for DEXlib to function properly. If this is not the case, some views will not work.

Development environment


DEXlib and STEPmod are developed on ( is a free Open Source software and standards development website. The website has CVSConcurrent Versions System, a revision control system, popular for open source and commercial software development. See: installed and made available to different development projects for free.

CVS - Concurrent Versions System

"CVS" is an acronym for the "Concurrent Versions System".

CVS is a "Source Control" or "Revision Control" tool designed to keep track of source changes made by groups of developers working on the same files, allowing them to stay in sync with each other as each individual chooses.

CVS is used to keep track of collections of files in a shared directory called "The Repository". Each collection of files can be given a "module" name, which is used to "checkout" that collection. DEXlib and STEPmod are two eamples of modules.

After checkout, files can be modified (using your favorite editor), "committed" back into the Repository and compared against earlier revisions. Collections of files can be "tagged" with a symbolic name for later retrieval.

You can add new files, remove files you no longer want, ask for information about sets of files in three different ways, produce patch "diffs" from a base revision and merge the committed changes of other developers into your working files.

This text has been copied from but has been slightly modified.

The two repositories at

One development repository and one mirrored read-only repository.
The development...
The read-only repository is used by anonymous users and the web based viewer utility on (www). The mirroring is not instant. Delays for up to 24 hours are not unusual.