There are several reasons why someone might prefer to use an older version of a browser:
In 2019, Waterfox development split into two distinct branches to serve different user needs: waterfox browser old version
If the security risks worry you, but you still need legacy features, consider these active forks: There are several reasons why someone might prefer
| Feature | Old Waterfox (56.x / 2019) | Modern Firefox / New Waterfox | |--------|----------------------------|-------------------------------| | | XUL/XPCOM (full browser modification) | WebExtensions (sandboxed) | | Multiprocess (e10s) | Partial / optional | Mandatory | | User agent | Easily spoofable to any string | Restricted | | Telemetry/Analytics | None | Minimal (opt-out) | | Plugin support (NPAPI) | Yes (Flash, Java, Silverlight) | No | | Older OS compatibility | Windows 7, 8, 10, macOS 10.9–10.14 | Windows 10+ / macOS 10.12+ | but you still need legacy features