Yes they have. Their biggest effort to date is SELinux: https://github.com/SELinuxProject

If you run Linux, you likely have NSA OSS on your machine.

You can find their public GitHub profile at: https://github.com/nationalsecurityagency

From https://published-prd.lanyonevents.com/published/rsaus19/ses... (page 7):

  >Why Did We Release Ghidra?
  > * Improve cybersecurity tools
  > * Build a community
  > * Educational Use
  > * Your tax dollars at work

I suspect they're just trying to expand US cyber capabilities and recruiting.

“If I go to the next capture-the-flag contest and I see some college students using Ghidra, I will be really excited” - Rob Joyce, senior cybersecurity adviser at NSA

Source: https://www.cyberscoop.com/ghidra-nsa-tool-public/

The seem to do a good amount of OSS work, and from looking at their github page, they have pretty active development on some projects going on.