NASM — The Netwide Assembler

This is the project webpage for the Netwide Assembler (NASM), an assembler for the x86 CPU architecture portable to nearly every modern platform, and with code generation for many platforms old and new.

Latest versions
Stable 2.16.03 Release notes Documentation
Release candidate 3.00rc15 Release notes Documentation
Development snapshot 3.00rc15-20250926 Release notes Documentation
All versions
Stable, release candidates, prereleases Development snapshots

Development Team

NASM was originally developed by Simon Tatham and Julian Hall, and is now maintained by a team led by H. Peter Anvin of Intel Corporation.

Currently active team members are:

... with support from many others, and we are always looking for more developers.

License

As of version 2.07, NASM is now under the Simplified (2-clause) BSD license. The details of the license are available in the documentation.

Bug reports

Please report bugs to our bug tracker. Unfortunately we are often unable to address things immediately, but we will look at them as soon as we can.