Java

Explanation of heap

• http://www.avricot.com/blog/?post/2010/05/03/Get-started-with-java-JVM-memory-(heap%2C-stack%2C-xss-xms-xmx-xmn...)

And the memory allocation in 32bit OS etc. Because JVM requires a contiguous memory, in 32bit OS the max VM heap allocation is usually 1.2G to 1.6G according to the blog. Although that's that the limitation of the VM. The alternative is to use 64bit OS.