You will find free software for playing abc files and also for converting them to MIDI files at:

http://www.gre.ac.uk/~c.walshaw/abc/

What the program is called, depends on your platform. They are listed there by platform.

I cut the snippets from the display on my browser and paste them into a file and then play the file with the software.

To the best of my knowledge there are no abc plug-ins from which you can play the snippets right from your browser. My (elderly) version doesn't even have .abc as a MIME type. There is some discussion there on how to have a browser launch the abc player.

Murray