Most of the DotNET libraries are written in C#, but they are designed to be used in VB.NET just as easily. In general, most of the libraries are LGPL, but there may be a few libraries under a different license. The status is a fairly accurate description of how often or how stable the system is. "Alpha" and "Beta" are both unstable, with potential changes happening quickly while "Stable" and "Mature" are for libraries that have stabilized. "Mature" projects are projects no longer under development and are considered stable.