Zend Guard

• Linux x86
• Windows x86 2000 / XP / 2003 / Vista (32 bit only)
• Mac OS X 10.4, 10.5

• 4.2.x through 5.2.x

Zend Optimizer

• Linux x86, x86-64
• FreeBSD x86 v5.x, 6.x
• Windows x86 2000, XP, 2003
  
• OS X (Intel & Power) 10.1-10.4 (32 bit only)
  
• AIX pSeries v5

• Apache 1.3.x
• Apache 2.0.x (Prefork mode only)
• Apache 2.2.x (Prefork mode only)
• IIS 5, 6 (FastCGI Only)
  

• 4.2.x up to 4.4.x (4.3.x and higher for Mac OS X)
  
• 5.0.x, 5.1.x, 5.2.x