Mozilla has released Firefox 156 and Thunderbird 156, continuing their new fortnightly update cycle. The latest versions introduce only a few new features — including a Mac auto-launch option and localized Wikipedia suggestions for French, German, and Italian users — but the real story is the growing ecosystem of forks that let users tailor their browsing and email experiences. From the stability-focused Waterfox to the privacy-hardened LibreWolf and the customizable Floorp and Zen browsers, alternatives abound for those who find Mozilla's faster pace unpalatable.
Firefox 156 is rolling out with modest additions. Mac users can now set the browser to launch automatically at login via a new Settings toggle, a feature The Register notes is already available in most operating systems. For users browsing in French, German, or Italian, Wikipedia suggestions in their own language now appear in the address bar, alongside ads from Mozilla partners (these can be disabled in Firefox Suggest settings).
Thunderbird 156, the email client managed by MZLA, offers slightly more substantial improvements. The release adds expanded troubleshooting information for OpenPGP issues and additional OAuth authorization options for POP3 and IMAP accounts. New enterprise policies allow administrators to control filters and user customizations.
For users who prefer a slower release cadence, Mozilla’s own Extended Support Release (ESR) versions — currently on version 153, released in late July — receive only security fixes and a single annual feature update. Beyond that, a handful of actively maintained forks provide alternative philosophies.
Waterfox, a longtime favorite, is based on Firefox 153 ESR. Its current version 6.7 retains compatibility with legacy XUL-based extensions years after Firefox dropped them, though the “Classic” branch that preserved older extension support is no longer maintained. Waterfox also includes a built-in ad-blocker, tree-style tabs, and works with global menu bars in desktop environments like Ubuntu Unity or Xfce. The developers have chosen a slower-moving, more stable release schedule with no integrated AI features.
LibreWolf takes a different approach: it stays close to Firefox’s rapid release cycle but strips out telemetry and adds privacy-focused defaults. If users are comfortable with Mozilla’s faster updates but want stronger privacy, LibreWolf is a direct option.
Floorp, a Japanese fork, emphasizes UI customization. Version 12.17.2 incorporates changes from Firefox 155 and offers multiple sidebars and other tweaks beyond what Firefox or other forks allow.
At the minimalist end, the Zen Browser offers a less cluttered interface with a focus on a streamlined experience, including tree-style tabs.
For Thunderbird users, Betterbird is the primary fork, currently based on Thunderbird 153 ESR. It is available for Windows, Linux, and Mac, and includes a portable Windows version that can run from a USB drive without installation.
The spread of forks reflects a longstanding tension: Mozilla’s push for faster innovation versus some users’ desire for stability, privacy, or specific features. As the project picks up the pace, the alternatives are likely to attract continued interest.
Analysis
Why This Matters
- Users who dislike disruptive updates or want stronger privacy/control now have credible alternatives that are actively maintained.
- The existence of a healthy fork ecosystem reduces dependency on Mozilla’s direction, especially on controversial decisions like telemetry, AI integration, or rapid release timing.
- Organizations that rely on Firefox or Thunderbird can choose ESR or custom builds (e.g., Waterfox, Betterbird) to align with internal IT policies.
Background
Mozilla adopted a faster release cycle in 2025, moving from four-week to fortnightly updates. This accelerated pace was met with mixed reactions, especially from users who had already seen major changes like the Firefox 57 “Quantum” release in 2017, which broke many legacy extensions. Forks like Waterfox emerged specifically to preserve that functionality. Now, alongside continued ESR options, a diverse set of forks offer different trade-offs between stability, privacy, customization, and speed of updates.
Key Perspectives
Mozilla/MZLA: They argue that faster releases allow users to receive security fixes and new web standard support sooner, keeping the browser competitive and secure. The ESR channel still exists for those who need a slower cadence.
Stability-focused users (e.g., Waterfox, Betterbird audience): They value a predictable, less disruptive experience. Many rely on legacy extensions or specific workflows that break with rapid updates. Forks that stay on ESR or maintain backward compatibility address this need.
Privacy-conscious users (e.g., LibreWolf audience): They want a Firefox-like experience with hardened privacy defaults and minimal telemetry, even if that means staying on a faster release cycle.
Customization enthusiasts (e.g., Floorp, Zen audience): They seek more UI flexibility than Firefox offers out of the box — multiple sidebars, minimal interfaces, or tree-style tabs without relying on add-ons that may break.
What to Watch
- Whether Mozilla adjusts its release pace or adds more opt-in features for forks to reduce fragmentation.
- The security posture of ESR-based forks: slower updates may mean later integration of critical patches.
- Adoption rates of newer forks like Zen and Floorp as they mature and attract larger user bases.