International Critical Commentary online

Not many hundred-year-old commentaries are go-to resources for serious Bible study. But various volumes of the International Critical Commentary have retained much of their value, even through a century of research and discoveries in biblical studies. Now most of the volumes are available for download at the Internet Archive in formats ranging from .pdf to .txt. You can find a list of available volumes here.

While you're there, you might want to browse for historical commentaries from others, such as Luther, Calvin, Aquinas, Cyril, and John Chrysostom. There are quite a number of older, out-of-copyright biblical commentaries at the Archive. I'd be interested to know of any others you might find worthwhile.

Update: Like just about all the resources linked from this site, items in the Internet Archive are free.