SWISH-E is based on SWISH, developed by Kevin Hughes. When Kevin Hughes stopped maintaining it, Roy Tennant (then at the University of California, Berkeley Library) requested in the mid-1990s to take responsibility for developing it further as a web indexing tool.
SWISH-E evolved from SWISH, crafted by Kevin Hughes. Following Kevin Hughes' withdrawal, Roy Tennant (at the time with the University of California, Berkeley Library) requested in the mid-1990s to assume control over its development as a web search engine.