NeweraHPC(http://newerahpc.googlecode.com) is a simple scheduler for scheduling tasks on a cluster of heterogeneous clusters. The program is completely opensource written under the GPLv2 license.
With the advancement of processors there is not much need of single system image and similar clusters. But the job can be done very efficiently using a simple scheduler that can fragment a job into smaller pieces and distribute it over the cluster of computers and then collect the results back. NeweraHPC does the same.
It is a very simple library based on C++ and uses posix libraries thus compatible with all the available UNIX platforms. It has all the basic services required like a simple garbage collector and can handle memory fragmentations very well.
There are two ways jobs can be distributed, first method is the traditional way wherein we can use some external application to process data and the data is fed in the form of independent files which are then written to a standard file which is then sent back to node which requested the job.
The second method is called NXI(Newera Extensible Interface) which is in the form of dynamic link libraries and contains docking functions. These functions are given data which is then processed and returned back to the node. This method is very efficient and embarrassingly parallel application frameworks can be written through it.
There are two versions of the program available in the repository, version 2 and 3.
Version 2 program is the older one and has the NXI implemented in it. It has been depreciated and it will be ported soon to the version 3. There is a test suite available with the program which can calculate the pi value to a million decimal places.
Version 3 contains the external binary implementation and is more sophisticated and will soon have the ability to work with NXI.
For more refere to http://www.newerahpc.com