Which program in Visual Studio lets me look into DLLs to see its API?
ILSpy is an open-source tool which allows you to browse an assembly's packages and classes and also to decompile code.
Another free-of-charge tool is JetBrain's dotPeek.
This is exactly what the Object Browser is for.
- Add a reference to the DLL.
- Right click it in the list.
- Click View in Object Browser.
For those coming from the old Visual Studio 6.0 days:
Dependency Walker is a nice free tool, that was formerly part of Visual Studio.
http://www.dependencywalker.com/
I like it still. Here is a screen shot: