Read-edid consists of two tools:

get-edid uses a VESA VBE 2 interrupt service routine request to read a 128 byte EDID version 1 structure from your graphics card, which retrieves this information from the monitor via the Data Display Channel (DDC).

get-edid uses architecture-specific methods for querying the video hardware (real-mode x86 instructions on i386, Open Firmware device tree parsing on PowerMac) and is therefore only available for i386 and powerpc architectures.

parse-edid parses this data structure and outputs data suitable for inclusion into the XFree86 or X.org configuration file. It is available for any architecture.