Bosworth-Toller Dictionary - "An Anglo-Saxon Dictionary" by Joseph Bosworth, edited and enlarged by T. N. Toller. Each page of the original is available in HTML and TIFF formats. Includes a search engine.
A Concise Old English Dictionary - John R. Clark Hall's "A Concise Anglo-Saxon Dictionary," second edition. Each page of the original is available in PNG and TIFF formats.
EOW Old English Translator - Online tool that translates single Old English words to their modern English equivalents, and vice versa. The tool is named Englisc Onstigende WordbÅc or EOW.
OEME Old English Dictionaries - An Old English to modern English dictionary and a modern English to Old English dictionary from the Old English Made Easy (OEME) project.
Old English Flash Cards - 1500 Old English words with their modern English equivalents. [PDF]