EUCALYPTUS — Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems — is an open-source software infrastructure for implementing Elastic/Utility/Cloud computing using computing clusters and/or workstation farms. The current interface to EUCALYPTUS is interface-compatible with Amazon.com’s EC2 (arguably the most commercially successful Cloud computing service), but the infrastructure is designed to be modified and extended so that multiple client-side interfaces can be supported. In addition, EUCALYPTUS is implemented using commonly-available Linux tools and basic web service technology making it easy to install and maintain. For more information click here.

Get the User Guide from this link http://open.eucalyptus.com/wiki/EucalyptusUserGuide_v1.4

eAccelerator is a free open-source PHP accelerator, optimizer, and dynamic content cache. It increases the performance of PHP scripts by caching them in their compiled state, so that the overhead of compiling is almost completely eliminated. It also optimizes scripts to speed up their execution. eAccelerator typically reduces server load and increases the speed of your PHP code by 1-10 times.

eAccelerator stores compiled PHP scripts in shared memory and executes code directly from it. It creates locks only for a short time, while searching for a compiled PHP script in the cache, so one script can be executed simultaneously by several engines. Files that can’t fit in shared memory are cached on disk only.

Installing From Source

unpack it by ::

$ sudo tar -xjvf eaccelerator-0.9.5.3.tar.bz2
$ cd eaccelerator-0.9.5.3/

Linux User Read README file

Windows User Read README.win32

Compile and install it with ::

./configure
make
sudo make install
make test

Add the below line to php.ini file

extension=eaccelerator.so

Check phpinfo()  and conform the module eAccelerator is loaded