GNU Parallel is the first thing I usually install on top of a standard Unix userland. It's almost a superset of xargs, with many interesting features. It depends on perl, though.

htop is also pretty much a great replacement for top. And ripgrep a great replacement for the find | xargs grep pattern.

Aside from that, I'm pretty content with the Unix userland. It's remarkable how well tools have aged, thanks to being composable: doing one thing and communicating via plain text.

I'm less happy with the modern CLI-ncurses userland. Tools like e.g. mutt are little silos and don't compose that well. I've migrated to emacs, where the userland is much more composable.

I don't feel the plain text portion has aged well at all in regards to composability. It leads to a lot of headache as the complexity of the task grows because of the in-band signaling and lack of universal format. I think it is high time the standard unix tools were replaced with modern equivalents that had a consistent naming scheme and pipelined typed object data instead of plain text.

If Unix pipes gained support for exchanging some kind of out-of-band signalling messages, then CLI apps could tag their output as being in a particular format, or even the two ends of a pipe could negotiate about what format to use. If sending/receiving out-of-band messages was by some new API, then it could be done in a backwards compatible way. (e.g. if other end starts reading/writing/selecting/polling/etc without trying to send/receive a control message first, then the send/receive control message API returns some error code "other end doesn't support control messages")

I have suggested this before: https://news.ycombinator.com/item?id=14675847

(But I don't really care enough about the idea to try to implement it... it would need kernel changes plus enhancements to the user space tools to use it... but, hypothetically, if PTYs got this support as well as pipes, your CLI tool could mark its output as 'text/html', and then your terminal could embed a web browser right in the middle of your terminal window to display it.)

ssh carthoris ls /mnt/media/Movies | grep Spider

(this is just an example). Note that in this example, we have two processes running on two different machines. Indeed, the OSs and systems on these machines may be, um... different. Indeed, I routinely include "cloud" machines in pipelines. Indeed, with ssh, the -Y (or -X) option can introduce a GUI to a part of the command.

I have wished that shar was part of SUS. Also, I find that "exodus" is useful (across Linux anyway -- the systems have to be "reasonably" homogenous). https://github.com/intoli/exodus