+1 for Quaternions. AFAIK, Math.NET Iridium had support for it, but it was discontinued because it was merged to Math.NET numerics. However, Quaternion didn't seem to be part of the merge process unfortunately. It'll be sweet if it can be included. Things like rotation matrices and quaternions are used a lot in 3D graphics and gaming, so I think it'll find a lot of use.

+1 for Quaternions. AFAIK, Math.NET Iridium had support for it, but it was discontinued because it was merged to Math.NET numerics. However, Quaternion didn't seem to be part of the merge process unfortunately. It'll be sweet if it can be included. Things like rotation matrices and quaternions are used a lot in 3D graphics and gaming, so I think it'll find a lot of use.