Tenrox is one of the oldest project management and professional automation services, having been launched by Upland Software in 1995. Tenrox closely resembles MS Project, both in terms of features available and appearance. It comes with project management, time sheets, billing and many other tools. Unfortunately, pricing details and availability on-premise aren't available on the vendor site. If you are looking for a free Tenrox alternative, available both in cloud and as self-hosted software with source code access, take a look at Bitrix24.
* Please note that the information may have changed since the publication. For current prices and features please visit Bitrix24 pricing page.