Q: what is the mackeeper?

Something you do not want to install.

Trashware that nobody needs, marketed very aggressively by a developer who has no ethical scruples at all. Stay away.

It's a suite of programs designed to assist your Mac with upkeep, malware protection, data encryption etc., that 99% of users here say it's the worst thing since Death.

You install it and it's a living ****, there are dozens of threads here about it.

I know when they first came out, there was a free trial and no way to uninstall it.

Anyway it's the bane of the Mac world, suckering unsuspecting users for their cash is what I gather.

It rates the lowest scores on App Store and on MacUpdate.com, there are dozens of highly heated threads about it from all over the Mac online world.

IMO they have spread a lot of cash around to buy reviews, advertising, over-inflate their ratings etc.

Here's one guys opinion and site with hundreds of responses. How to correctly uninstall it.

http://applehelpwriter.com/2011/09/21/how-to-uninstall-mackeeper-malware/

Here's another

http://www.macupdate.com/app/mac/33710/mackeeper

You can search the Apple forums here for more even threads on MacKeeper.

Wow!  Thanks for the heads-up, everyone!