Excerpted from TheFreeDictionary:
2. b. Of no practical importance; irrelevant.
From the Kemsley Guide to Bad Writing:
1. Unable to understand when to use the word “moot”, as in “moot point”.
In the past two days, I’ve seen two technical articles online (that I won’t embarrass by linking) that have used “mute” when they clearly intended “moot”. One was a blog post, which is a bit forgivable, but the other was a 3-page edited (?) article on a well-known technical website. I may have been trained as an engineer, but my schooling did include some English courses along the way (plus some time with an English major as a university roommate), and I expect anyone who is going to take on writing lengthy articles on any subject to at least make sure that their use of the language is correct. Otherwise, there will be some people — like me — who judge a writer’s overall capabilities based on their inability to use the correct word in a sentence.