Yes, I have a simple version control system. I have some simple tools based on macros for my favorite editor KEdit and some scripts based on Rexx. So far they have been fine.
The biggest problem I had was documentation for .NET. I found, read, downloaded, and abstracted 4000+ Web pages from Microsoft's MSDN and have about another 1000 Web pages from elsewhere. These are in four batches -- the languages, especially Visual Basic .NET, for SQL Server, for communications including TCP/IP and ASP.NET (for the Web pages), and the rest for Windows in general. I also have documentation of my own, mostly just text but some with the math from Knuth's TeX.
So, in the code and other documentation, I put links to relevant documentation. The links in the code look to the compiler like comments. I insert and use the links with editor macros. In the end, I can display a page of documentation with one keystroke to my editor. Works well enough.
For help with versions, I have a very heavily used editor macro that inserts a time-date stamp or two of them delimited with BEGIN and END as comment blocks with time-date stamps.
Sure, if I hire some people, I'll have to have something better. But in our AI project at IBM's Watson lab, we did quite a lot of software development, including shipping some IBM Program Product code, with less in versioning tools than I'm using.
Right along I've been thinking that if my startup works, then one of the first steps up will be some audio-video facilities, a lecture hall, good audio and video recording and then editing, etc. Then we will call in experts on various topics, have them lecture, maybe sell their book or some such, record it all, and have it on-line for everyone as documentation. So, we'll have people who worked out good means of versioning, backup and recovery, archiving, data security, disaster protection, network security, server monitoring, server construction and software installation, SQL Server performance, LAN performance, code testing and reviews, developer training, the servers, racks, LAN, electric power, backup power, HVAC, real estate for floor space, telephones, e-mail, etc. Yup, I'll need a COO!
All these topics have been done well lots of times in the Fortune 100 and more, and lots of people have been there, done that, and still have the T-shirt. Likely don't necessarily have to hire them but can fly them in for 1-3 days and capture what they have to say. Later in the growth may have to do some things that are original, but can have a lot of growth before that.
Similarly, while I'm developing on Windows with no use of Linux at all, I make no use of Visual Studio; I greatly prefer my favorite text editor KEdit and its macro language Kexx, essentially Rexx.
I'm not saying that others should do what I'm doing. By far my favorite tools are KEdit and Rexx. Next comes D. Knuth's TeX.
I accept that if I had 50+ software developers then they would likely be heavy users of Visual Studio and GitHub. But for me, for now, they aren't worth the botheration.
Botheration, mud wrestling with software, has, after poor documentation, been my biggest obstacle.
ALL the work unique to my project has been fast, fun, and easy, the idea, applied math, code, etc. Thus I have a real sore spot about new, external tools -- my experience with such external things has been botheration I call mud wrestling. The time wasted has not been hours, days, or weeks but far beyond that.
IMHO the biggest bottleneck now in the future of computing is poor documentation. Second is mud wrestling with new products including tools.
The code is 100 K lines of typing but about 25,000 programming language statements, that is, 25 KLOC. That is, there are a LOT of comments and links to documentation in the code.
