I am a member of the pragmatic programmer mailing list. One of our list members, Joe Van Dyk, sparked off a discussion titled “What goes into version control?”. It was a great question that I had to find an answer for myself over the years, because there were no actual rules.

I personally recommend that you put into your version control all of the things that will allow you to jump from one machine onto to another, checkout your project, and start your work. This recommendation comes in particularly handy when your primary machine is on the blink.

In this vein, items that get placed into my version control include documentation from the customer, library documentation, library binaries, keystores, and even IDE project files. I do not include class files, or jars that get created by my “build” or “dist” target.

You might also consider placing into your version control other types of files that should be safely stored in case you become unhinged and start eating your laptop while yelling “melted butter”. Believe me, if you have ever programmed in EJB 2.x or even 1.x, you have, at one time or another, thought about eating a laptop.

This particular scenario has forced me to put into my version control items like customer invoices, RFPs, copies of emails, agreements, electronic receipts, etc. It is a sound insurance policy to do so. This rule falls in line with a blog entry that I read a long time ago by Joey Hess, who likes to keep his life in subversion. Joey's blog entry is the main reason for my transformation into the digital packrat that I am today.

Lastly, I highly recommend that your version control be somewhere other than your office. In fact, it should be in a completely different building, unless you have a very good emergency plan. I currently pay $200+ a month to kattare.com for them to host my dedicated server. The dedicated server contains my web site and blog, my version control, my build automation tool, and whatever else I can put into it. The cost may seem high to you, but if your career is as a self-employed programmer, or even an overzealous company programmer, this option is a no-brainer. Plus, it's a nice business write-off.

Let me know what you, as a Java programmer, put into your version control. If you are part of a company development team, what are you allowed or not allowed to put into your version control?