"The Liberation fonts are designed as drop-in replacements for
the widely-used proprietary fonts like Times New Roman, Arial,
Helvetica, Courier New, etc. The Liberation font pack consists of
three sets: Sans (a substitute for Arial, Albany, and Helvetica),
Serif (a substitute for Times New Roman) and Mono (a substitute for
Courier New, Cumberland, and Courier).
"The SIL organization offers an impressive collection of fonts
released under the Open Font License. Here you will find fonts
designed for specific purposes (e.g., the Antika font is designed
especially for literacy education) and specific languages (e.g.,
Arabic Script Unicode fonts) as well as all-around high-quality
fonts like Gentium and Charis."