GridGain is a Java-based grid computing framework that makes grid computing simple. It provides an innovative compute grid and integrates with data grids. Key features include MapReduce programming, zero deployment where applications can run unchanged on a grid, on-demand scalability, fault tolerance, and integration with data grids and messaging middleware. It has over 20,000 downloads and supports pluggable aspects like communication, discovery, and load balancing through its SPI-based architecture.