The evolution of IDA Pro (Interactive Disassembler) represents the history of software reverse engineering itself. Since its inception in the early 1990s by Ilfak Guilfanov, IDA has transitioned from a simple DOS-based disassembler into the industry-standard multi-processor, multi-OS interactive analysis tool used by security researchers, malware analysts, and software engineers worldwide. The Early Era: DOS and 16-bit Origins
If you're starting today, is the only version you can legally buy, unless you find an old resold perpetual license (rare, expensive). For hobbyists, IDA Free 7.0 or Ghidra are alternatives. ida pro versions
Regardless of the specific version, IDA Pro provides a core set of advanced tools: IDA Pro: A Comprehensive Guide to Versions and
In IDA: Help → About shows: