Website link checker - techy help plzkthx

[Brazen]

Can any of you IT types recommend me website link checking software please?

As well as internal and external website links, it needs to look for broken anchors, it needs to be downloadable to run against development versions of sites and should be one click to check an entire site but can be restricted to a sub-paths.

It's for work use, so there's the possibility of paying, but open source would be better.

Ta!