Bootstrap
Twitter’s Bootstrap toolkit is by quite a wide margin the most watched project on GitHub. so, to a first approximation, everyone is using it—except me.
Feeling left out, I did the obvious thing of clicking the big “Download Bootstrap” button on the front page, but the zip file to which it links includes the entire Bootstrap source and documentation. I don’t want to fiddle with source files. I just want to use Bootstrap.
More usefully, but less obviously, there is a rather helpful download page which allows me to select just the components and plugins that I want and to amend the default colours and fonts before downloading. This gives me solitary .js and .css files, along with minified versions, that include everything. I guess that this is what 90% of users will want.
Two days later: I have had a play and I cannot think of a reason for me to to use anything else. Bootstrap is really nice.