The invention relates to a computer device for managing documents, in particular software projects developed in co-operation. A memory stores contents of documents having time references. An extractor separates the document contents into document elements. A signature generator returns signatures of element contents. An imprint generator associates for each document the time reference thereof and the signatures of its elements. A time clock module calculates the results of a time election function. A supervisor operates the generator on the document contents. For each signature value, it calls the time clock module with a list of imprint time references containing the signature value. A unified time reference is obtained for each signature value. Each signature value and its unified time reference are stored.