Expressions in use:
| OK to use | Avoid (and why) |
| Free / Libre / Open Source | |
| Free and Open Source | |
| Open Source | opensource or open source or open-source Ref.: https://perens.com/2017/09/26/on-usage-of-the-phrase-open-source/ |
| proprietary software | Commercial software as it's ambiguous. |
See also Branding Guidelines