Such asynchronous (non-simultaneous) contributions are very efficient in time, as group members need not assemble in order to work together. Generally, managing such work requires software;[7] the most common tools for editing documents are wikis, and those for programming, version control systems.[citation needed] Most word processors are also capable of recording changes; this allows editors to work on the same document while automatically clearly labeling who contributed what changes. New writing environments such as Google Docs provide collaborative writing/editing functionalities with revision control, synchronous/asynchronous editing.