The Chinese Text Project is an open-access digital library whose goal is to make available a wide variety of Chinese texts from ancient periods. Though the site focuses on ancient texts in particular, texts from the Tang, Song, and Ming dynasties are well represented as well. Texts are generally taken from open-source documents published elsewhere on the internet, but there are also original transcriptions as well.
The CTP also brings together a variety of resources for the study of ancient Chinese texts, including dictionaries, bibliographies, and other resources. There is also an active discussion board where questions of transcription and translation are frequently asked. The site continues to be updated regularly.