Is it possible to embed a pre-existing DLL into a compiled C# executable (so that you only have one file to distribute)? If it is possible, how would one go about doing it?
Normally, I'm cool with just leaving the DLLs outside and having the setup program handle everything, but there have been a couple of people at work who have asked me this and I honestly don't know.
Yes, it is possible to merge .NET executables with libraries. There are multiple tools available to get the job done:
In addition this can be combined with the Mono Linker, which does remove unused code and therefor makes the resulting assembly smaller.
Another possibility is to use .NETZ, which does not only allow compressing of an assembly, but also can pack the dlls straight into the exe. The difference to the above mentioned solutions is that .NETZ does not merge them, they stay separate assemblies but are packed into one package.
.NETZ is a open source tool that compresses and packs the Microsoft .NET Framework executable (EXE, DLL) files in order to make them smaller.
You could add the DLLs as embedded resources, and then have your program unpack them into the application directory on startup (after checking to see if they're there already).
Setup files are so easy to make, though, that I don't think this would be worth it.
EDIT: This technique would be easy with .NET assemblies. With non-.NET DLLs it would be a lot more work (you'd have to figure out where to unpack the files and register them and so on).