The Chinese Text Project created by Donald Sturgeon aims to present accurate and accessible copies of ancient (in particular pre-Qin and Han dynasty) Chinese texts in an organized and searchable format, together with various features and tools for manipulating the texts. These include facilities ranging from full-text search, parallel passage markup and search, and scanned source texts, through to such things as user-defined metadata. This site is available in English and Chinese, with traditional or simplified characters.
More information: http://ctext.org/introduction.