Sending Infrared Signals (simulating remote controls)

I have run a rather exhaustive search of the internet and have found
surprisingly little material on sending infrared signals. I was hoping
to find software that can at least send specific frequencies. Ideally,
it would be able to rotate through frequencies and combinations.

Where can I find one of the following software to send infrared
signals (trigger electronics) or help on how to program such
functionality. I have Visual Studio .NET installed if there is some
code I could use.