Submission + - Firefox 153 was released today (firefox.com)
But the most important feature is that this version is an ESR, and therefore, defines the feature set of ESR for the next year. Why is being an ESR so important you ask?
1.) ESR, and not "normal (a.k.a. Rapid Release)" FireFox is the OotB browser for many important distros, like Debian, RHEL, Kali, TAILS, Suse Leap, Slackware and such.
2.) Many organizations large and small standarize on FireFox ESR as their default browser, regardless of the default browser that comes with their OS.
3.) FireFox ESR is the basis for many projects downstram, like WaterFox or KaiOS. All these projects will inherit for a year whatever ESR brings to the table today.
4.) Many ISVs and SaaS providers, if they certify their wares for FireFox at all, certify for the ESR version only.
Please notice that ESR 153 will NOT be offered as an automatic update until 2 months from now (ESR 140 will still be supported), If you want it now, you need to do a manual download and install.
Also of note, ESR 115 will be supported until march 2027. If you have unsupported versions of MacOS or Windows (like 7 or 8.x) this is the version to get, but even Mozilla themselves cautions about running a supported browser on top oh an unsupported OS:
"Note that Microsoft ended official support for Windows 7, 8, and 8.1 in January 2023. Unsupported operating systems receive no security updates and have known vulnerabilities. Without official support from Microsoft, maintaining Firefox for outdated operating systems becomes costly for Mozilla and risky for users. "