A web browser is a client program for accessing the World Wide Web. Its main feature is the loading of HTML pages over HTTP(S) connections and rendering them. There are moderate-sized web browsers as well as huge and bloated ones.

Today, many WWW sites are entire applications that depend on complex client-side programmability with ?Javascript or ?WebAssembly. This makes the modern web browser the most common application software platform. Supporting it may therefore be useful, even though exclusively supporting such an unreliable target is not that wise from the permacomputing point of view.

Programs written in C, ?C++ and some other languages can be compiled into web browser applications with LLVM-based compilers such as Emscripten and ?Zig. This makes it possible to minimize web-specific code and to use the same source code for native applications.