From version 6.0 onwards, development of the core platform is switching away from VB.NET to C#
From the start, DotNetNuke has been developed in VB.NET, although modules could be written in other programming languages (including C#). For the last year a version of the core platform written in C# has also existed.
Now the core framework is switching to C#, from the release of version 6.0 (expected second quarter of 2011), although separate module projects (such as the Forums, Blogs and Feedback) can still be developed in either VB.NET or C#.
C# has gained strength over VB.NET in more recent years, with the majority of Microsoft products built using it and a greater demand for C# developers in the jobs market. Other reasons given for the switch included the greater availability of source code examples in C#, a perceived performance benefit and greater acceptance for building enterprise applications.
Pure Systems develops applications in both C# and VB.NET, including standard modules and bespoke modules for DotNetNuke written in both languages.