Let me give you an example:

  1. Erwann installs PhpWebGallery on his website and creates a new graphical theme. He wants to share his theme. Erwann registers to the PEM installed on phpwebgallery.net, creates an extension Erwann's theme and a first revision of his extension. Erwann says that this first revision is compatible with PhpWebGallery 1.6.0 and 1.6.1. Anybody can now see Erwann's theme.
  2. 2 weeks have passed and Erwann realizes there is a bug in his theme. He fixes the bug, create a new revision of his extension and upload it in PEM. Anybody can see that a new revision is available and what's new in it.
  3. 6 months have passed, Erwann installs the brand new PhpWebGallery 1.7.0 that brings so many new features, including theme modifications. Erwann modify his theme to make it compatible with PhpWebGallery 1.7.0. Erwann creates a new revision of his extension, described as compatible with 1.7.0.

Here is a brief history of PEM:

  1. April, 2005. On phpwebgallery.net, the idea to create a section dedicated to user extensions was born.
  2. Summer, 2005. Sephi takes the lead on development after I described the specifications and helped him to define the required data model.
  3. December, 2005. Sephi finishes his first usable version of the extension manager, I install it on phpwebgallery.net
  4. March 31st, 2006. PEM was born as a standalone opensource project.
  5. January, 2007. Koha installs PEM to encourage user contributions.
  6. April, 2007. Talend sponsors PEM, ie let me contribute to PEM code during my work time.
  7. May, 2007. PEM is installed on TalendForge, the community website of Talend Open Studio.