Zida Tomato BIOSes for Socket 3

Socket 3 (237pin) was a series of CPU Sockets for various x86 microprocessors. It was sometimes found alongside a secondary socket designed for a math coprocessor chip, in this case the 487. Socket 3 resulted from Intel's creation of lower voltage microprocessors. An upgrade to Socket 2, it rearranged the pin layout.
See: https://en.wikipedia.org/wiki/Socket_3.