GridRepublic is described as 'customized version of the BOINC software designed to simplify installation and participation by the average computer user' and is an app in the Education & Reference category. There are more than 10 alternatives to GridRepublic for a variety of platforms, including Linux, Mac, Windows, Online / Web-based and Android. The best alternative is BOINC, which is both free and Open Source. Other great apps like GridRepublic are Folding@home (Free), Apache Mesos (Free, Open Source), Charity Engine (Free, Open Source) and Foldit (Free).
DIET is a software for grid-computing. As middleware, DIET sits between the operating system (which handles the details of the hardware) and the application software (which deals with the specific computational task at hand).
PiCloud gives every scientist, developer, and engineer a supercomputer at their fingertips. We make it easy to leverage thousands of cores of computational power for high performance computing, batch processing, and scientific computing applications.