Flex License Manager is a form of DRM used on IRIX and other UNIX systems to lock out features and programs and authenticate them in a centralized form.
As prefaced, this is an early form of software DRM. The /var/flexlm/license.dat file is a plaintext file containing all centralized flexlm license keys. It contains the registrant, serial info, expiration date etc.
While IRIX Network does not condone piracy, a HaxForce FlexLM license is available for download here: