What is this connector called?

[mojoe]

This is a very common connector, but I don't know what it is called. I'd like to order some. Sorry for the blurry picture. My phone camera doesn't focus well this close.

[KE5FX]

Lots of vendors offer connectors like that, but the name you probably want to look at first would be Molex.

[ajb]

Molex's KK series and TE's MTA series both have very similar headers.  The spacing of the slots in the locking tab may be customizable for keying purposes, in which case you might not find a perfect match off the shelf.

[Tomorokoshi]

Yes, looks like MTA100 with the slots to accommodate the side tabs from wire-end connectors. Are there three separate cables that plug into this side-by-side?

[mojoe]

I don't have any mating cables, but I assume it was just one plug.

[tuvix]

Vertical friction lock, polarized molex connector, etc. Here are the ones I buy from Mouser.
http://www.mouser.com/Search/ProductDetail.aspx?R=22-23-2021virtualkey53810000virtualkey538-22-23-2021

Mating header:
http://www.mouser.com/ProductDetail/Molex/22-01-2021/?qs=sGAEpiMZZMtVoztFdqDXO9AtJeNgVE9K

The last two digits set the pin count. For instance 21 = 2 pin, 23 = 3 pin, etc. Be careful to order bulk crimps NOT tape reel. they never fit right in the housings.