Aliados is a CP/M 80 emulator. Instead of emulating a machine and running some variant of CP/M on it, it emulates only the microprocessor and captures all CP/M system calls to execute natively. It does not need to create disk images, but reads and writes on the native filesystem all files that match the CP/M naming conventions.
ADTPro transfers disks to and from Apple II and Apple /// computers and the modern world using any of these communications methods: serial/USB, UDP via the Uthernet or LANceGS Ethernet cards, or audio via the Apple's cassette ports. ADTPro has comprehensive bootstrapping support for otherwise diskless Apple IIs. The home page includes extensive tutorials for getting started.
AtariSIO is a Linux kernel driver module plus a small set of tools that implement the Atari 8-bit (400/600/800/XL/XE) computer series SIO protocol. The kernel driver handles the low-level parts and provides a simple interface for user space applications. This package contains two tools: atariserver, an Atari disk drive emulator (similar to SIO2PC or APE for MSDOS), and atarixfer, a tool to transfer disk images to/from a connected Atari disk drive.
Audiotap is a program for conversion between .TAP files and Commodore 64 tapes. It can read WAV files containing the sampled sound of a tape and convert them to .TAP files, and can generate WAV files to be recorded on a tape and used on a Commodore 64. It can also record .TAP files from the sound card and turn .TAP files into sound played to the sound card. It does not require custom-built cables, just plain audio cables connecting the sound card and a normal audio tape player/recorder.
Avrora is a set of tools for programs that run on the AVR series of microcontrollers produced by Atmel. It contains a flexible framework for simulating, analyzing, and optimizing assembly programs, and provides a clean Java API and infrastructure for experimentation, profiling, and analysis.