The Compatible Time-Sharing System (CTSS) was one of the first time-sharing operating systems; it was developed at the MIT Computation Center. CTSS provided interactive terminal access for online users and interleaved conventional batch jobs on a machine-time-available basis. CTSS evolved over the years and in the Fall of 1963 began daily operations at the Laboratory for Computer Science as well as at the MIT Computation Center, where it operated until July 1973.