East Asia Library has recently added a few major Chinese full text databases to the collection:
Zhongguo ji ben gu ji ku 中國基本古籍庫
includes more than 10,000 full-text traditional Chinese works. Original images also available. Full text searchable.
Si bu cong kan 四部叢刊
A collectaneum compiled by the Republican period (1911-1949) scholar Zhang Yuanji 張元濟 (1867-1959). It includes 504 texts arranged in three series. Special font file should be downloaded for proper display of Chinese characters.