Or is it just a neutral term for tidal waves?
tsunami.js – would it be offensive?)
I would say "not necessarily"; but, it definitely doesn't have positive connotations...
One might think of it as
Hmm, evidence? Well, the word "earthquake" is definitely not a positive word by itself, right? It has more neutral or negative connotations (i.e.,
<= 0). But, I don't know how to provide evidence of that...
There is a word, アクセス津波 (access tsunami), which is when there are a lot of site views/accesses in a short period. When used in this sense, I guess the blog owner would be happy :)
At any rate, I don't think you'll realistically be offending many people by using "tsunami" (unless your project is destructive, obviously).
By the way, what will your project be doing?