Red Hat recently announced the availability of a family of fonts they had commissioned from Ascender Corp. The goal behind the fonts was to be metric compatible with the nearly ubiquitous Microsoft fonts Arial, Courier New, and Times New Roman. I put together a comparison of the new »Liberation« family of typefaces along with their Microsoft metric compatible counterparts. To provide a little more additional information, I've also included the Bitstream Vera family. Bitstream Vera seems to be made available under a fairly liberal license. The Liberation fonts are made available under the GPL with the standard font embedding exception.
Overall, I can't say the Liberation fonts feel particularly notable, but given that their main purposes is to provide a »free«,as in Freedom, replacement for deeply entrenched Microsoft fonts, I don't imagine originality was really considered as a goal. The fonts are available for download from here.