Obviously I should have looked at SourceForge statistics before deciding which
software to use instead of basing my decision exclusively on Google
page count so here we go:

Zen Cart

  • Development Status: 5 – Production/Stable
  • Developers: 5
  • Activity Percentile (last week): 99.85
  • Latest Release: August 21, 2005
  • Google Hits: 2,110,000

osCommerce

  • Development Status: 4 – Beta
  • Developers: 3
  • Activity Percentile (last week): 92.80
  • Latest Release: July 12, 2003
  • Google Hits: 13,500,000

Initially, based on pure Google hit count I decided to try osCommerce first, however after having lots of troubles with PHP5 and internationalization and also checking out SourceForge statistics I decided to abandon osCommerce in favor of Zen Cart. In addition, Zen Cart seems to be actively developed unlike osCommerce, whose development seems to be completely frozen right now.