I’m currently working on a Unity3d project, and often find myself in need of 3rd party DLLs. Unity supports .Net 3.5 libraries through an old version of Mono. Most libraries these days are distributed via Nuget packages and usually only with the latest version of the .Net framework. I’ve found myself having to find or create back-ports of those libraries. Unity isn’t the only framework I’ve had this problem with and portable class libraries are on attempt to solve this (but sadly they’re not supported on Unity).
Most of the time, this is actually really simple. Add a reference to System.Threading, the TPL back port and there are no other changes required.
Recently, I’ve been focused on performance and I’ve needed to back port Distruptor-net and Microsoft.Io.RecyclableMemoryStream. These libraries are small; I only need to use maybe one public class from each, yet I have to include a DLL each time. For just these two public classes I’ve needed to add three DLLs. I could ILMerge them with my assemblies; but that can cause other problems.
I’d rather get a source. I’ll probably not need to upgrade these libraries, given their simplicity I’d like to be able to just get a single source file and drop that into my project. This is a work flow that works anywhere; even in doesn’t support Nuget. I wouldn’t have had to create back ports, the source just compiles (you could even use the preprocessor macros to hide some of the compile time differences).
There are actual performance reasons for not having lots of libraries; most people don’t care but the JIT can’t work across assembly boundaries (although to be honest this level of performance doesn’t bother me too much, but why deliberately slow your program down?).
Nuget actually supports distribution of sources; when you install a package it will automatically add them to your csproj. I’d even commit these files into version control. This will save you from having to do a package restore too.
People often want to share snippets of code. Sometimes they do this by creating a misc/util library; usually I don’t want all the baggage. I’ve written about that before here.
Next time you want to create a new library, ask yourself, what is better; one cs file or another DLL to manage and version?