Java Runtime Enviroment (JRE) 1.5.0 or later
Pentium III  1 GHz CPU
512 MB RAM
1024 x 768 screen resolution 
40 MB of free hard drive space

Recommended requirements

Java Runtime Environment 1.6.0 or later
Intel Core2Duo 1.83 GHz or faster CPU
2 GB or RAM
1680x1050 screen resolution
40 MB of free hard drive space