[2] Like the Suite it is descended from, Classilla offers E-mail (POP/SMTP), Usenet (NNTP), Gopher, FTP and World Wide Web (HTTP) access, using a modified version of the Gecko layout engine called Clecko.

[12] On March 29, 2021, Kaiser released the final versions of both Classilla and TenFourFox and announced the cancellation of official support for both projects, citing increasing technical issues.

On the other hand, its layout capability is more current than WaMCom or Mozilla 1.3.1, and Classilla has a more modern JavaScript interpreter than iCab and better support for the Document Object Model although it is also still deficient compared to mainline Gecko-based browsers.

It is perceived by users to be more stable and quicker to render than iCab,[15][16][17][18] important as the classic Mac OS relies on cooperative multitasking and has very limited support for memory protection—any application crash could hang the entire system.

[11] The presence of NoScript, along with the unusual nature of the classic Mac OS, is thought to add some level of protection, although it was the avowed goal of the developers to reach security parity with modern Mozilla-based releases[11] and repair outstanding bugs.