Flash Builder 4 System requirements

Flash Builder 4 for Windows (Standard and Premium editions)
2GHz or faster processor
Microsoft® Windows® XP with Service Pack 3, Windows Vista® Ultimate or Enterprise (32 or 64 bit running in 32-bit mode), Windows Server® 2008 (32 bit), or Windows 7 (32 or 64 bit running in 32-bit mode)
1GB of RAM (2GB recommended)
1GB of available hard-disk space
Java™ Virtual Machine (32 bit): IBM® JRE 1.5, Sun™ JRE 1.5, IBM JRE 1.6, or Sun JRE 1.6
1024×768 display (1280×800 recommended) with 16-bit video card
DVD-ROM drive
Eclipse 3.4.2 or 3.5 (for plug-in installation)

Flash Builder 4 for Mac OS (Standard and Premium editions)
Intel® processor
Mac OS X v10.5.6-10.6
1GB of RAM (2GB recommended)
1GB of available hard-disk space
Java Virtual Machine (32 bit): JRE 1.5 or 1.6
1024×768 display (1280×800 recommended) with 16-bit video card
DVD-ROM drive
Eclipse 3.4.2 or 3.5 Carbon version (for plug-in installation)

Flash Builder 4 data-centric development features
Adobe® ColdFusion® server: ColdFusion 8.0.1 or 9
J2EE server: BlazeDS 4 or Adobe LiveCycle® Data Services 3
PHP server: PHP 5.2 or Zend Framework 1.9.4 (included with Flash® Builder™ 4)
Web services: WSDL 1.1
Flex 4 SDK
Windows XP Professional with Service Pack 2 or 3, Windows 7 (32 bit), or Windows Vista (32 bit)
Mac OS X v10.5.6-10.6 (Intel only)
Ubuntu 9.10
Fedora Core 12
Language versions
Adobe Flash Builder 4 software is available in the following languages:

Chinese Simplified
English
French
German
Japanese
Russian