Difference between http://jigsaw.w3.org/css-validator/ and http://www.css-validator.org/ css validators?

I tried validating my css using both validators and they give different
results! http://www.css-validator.org/returns much more errors (245 in my
case) than http://jigsaw.w3.org/css-validator/ (which returned 24 errors).
What is the difference between these to? Aren't they both under w3c?

Options I used for http://jigsaw.w3.org/css-validator/:

   - Profile: CSS level 3
   - Medium: all
   - Warnings: all
   - Vendor extensions: default

I also tried changing Vendor extensions value, if I set it to Errors I get
about 100 errors, if I set it to warnings I get same amount of errors as
when default, which is 24.

Options I used for http://www.css-validator.org/:

   - Profile: CSS level 3
   - Medium: all
   - Warnings: all

Examples of errors not returned by css-validator but not by jigsaw:

   - ".kill-flicker: Property backface-visibility doesn't exist : hidden
   hidden" Line no: "5"
   - ": Unknown pseudo-element or pseudo-class ::-moz-focus-inner
   [-moz-focus-inner]" Line no: "225"

Thank you,
Martin