Aster Data Systems, the coming data warehouse company, has leveled the playing field and made it possible for .NET developers – what it calls the “other half” – to leverage the vaunted MapReduce programming model popularized by Google to write native “Big Data, Rich Computation” applications.

Aster’s nCluster and nCluster Cloud Edition, the MPP databases that already tightly integrate SQL with MapReduce, now let .NET developers write MapReduce functions in Microsoft’s C# language and have them execute in the database in the name of data-driven applications and business analysis.

The move extends nCluster’s existing support for Java, Python, Perl and C++.

MapReduce is used to process large unstructured data sets distributed across thousands of nodes. Aster’s In-Database MapReduce enables developers to harness MapReduce’s powers while managing their data in nCluster, a highly scalable RDBMS for data warehousing and analytics.

Aster says nCluster was the first database system to offer enterprise-class MapReduce capabilities such as integration with BI and ETL tools, SQL support, backup and recovery, transactional data consistency and support for interactive as well as batch analytics.

Since, according to Forrester Research, 62% of enterprises develop on .NET and 43% of enterprises use C# for development or maintenance, Aster is counting on the move to tickle its popularity.

Aster is backed by Sequoia Capital, JAFCO Ventures, IVP, Cambrian Ventures and First-Round Capital, as well as by David Cheriton, the billionaire Stanford professor who co-founded both Granite Systems (sold to Cisco) and Kealia (sold to Sun) with Andy Bechtolsheim and reportedly hooked Sergey Brin and Larry Page up with Kleiner Perkins, which explains his money.

The company’s biggest (Amazon) cloud user is ShareThis, which reportedly has a 10TB data warehouse on its way to 30TB by the end of the year. Its largest on-premise user is MySpace Music with a 200TB data warehouse. Other customers include LinkIn and Coremetrics.

The widgetry works on low-cost x86 hardware clusters and can plow through terabytes of data in minutes to, say, spot cheats playing online poker.

Aster says it supports any analytic application with a Linux runtime. It brags that its “written by one, used by many” functions cleanly separate the roles of analyst and programmer.