I wrote this z80 emulator library in 2008 after being dissatisfied with other emulators for one reason or another. It aims to be cycle-accurate by modeling the number of T-cycles per instruction. See the Z80 CPU User Manual for details about T-cycles.
Libzel is very low level. It operates one instruction at a time, calling callbacks to read memory, perform I/O, and handle interrupts. No assumptions are made about memory layout or peripheral organization.
None of the standard Zilog peripherals are implemented and they must be handled by the callbacks.
Libzel was used to emulate the Sequoia AVC Advantage voting machine as described in Checkoway et al.'s Can DREs Provide Long-Lasting Security? The Case of Return-Oriented Programming and the AVC Advantage.