Religion, by core definition, doesn't necessarily mean something mystical, it just means a firm set of community values and traditions that each individual conforms to.
For example, Star Trek is a religion to some people - all their friends are obsessed with it, they've read all the books, never missed a local convention, etc. Their mental map of knowledge could be centered around Star Trek, and when discussing a philosophical or scientific idea, for example, they think back to the episode that touched upon it.
If you're involved with an open-source project, use it regularly, read its community forums and hang out in its chat-room, you might say it's a religion you subscribe to, probably one of several.