The downloads page has two zip files for each release: the “standard” zip and the “full” zip for use with AMD, e.g., RequireJS.
I originally pushed for this with the idea that most folks just needed the standard version, which is a smaller download and easier to get our heads around once unzipped. However, the website statistics show that downloads are split about 50/50 between the two versions. I suspect many users download the full version just in case.
I suppose we should streamline this to just a single full zip to remove the confusing decision (still not as confusing as downloading eclipse). Thoughts? Did this confuse you?