Since no one mentioned Plan 9, I thought I will mention one of the many features that makes Plan 9, one notch above Unix to make it easy in the web era.
In Plan 9, literally everything has a file abstraction. This also includes sockets. So, even shell programs can be network programs without external programs like curl or wget or anything like that. For anyone interested, look at webfs(4). You may say that this can be implemented with fuse. But having something first class, designed to operate well within the file abstraction, is very different from something that has been added as an afterthought. In some sense, the BSD folks who added sockets into Unix really screwed it up and missed the Unix philosophy altogether.