How do you make the browser your own user enviroment?

> As a user environment where I can download packages and visual apps to run locally?

It's almost like the computer needs the ability to run applications separate from the browser, to achieve tasks that are unrelated... What an idea that would be!

However some of the tasks you mention are very trivial. It seems hard to believe that you think a dedicated "app" is required for example your first example "convert a string to caps". This can be solved several ways on macOS out of the box.

TextEdit: New Document, (paste content), select all, Edit > Transformations > Make Upper Case

Terminal: pbpaste | tr 'a-z' 'A-Z' | pbcopy

Edit: oh and I forgot to mention, Preview.app (also built in) will open a gif as a series of image frames, so you can do as you wish with them.

This is hard to answer, because you could get good advice from two opposing directions:

- learn to use the command-line more, relying on documentation like http://cht.sh/magick, and http://cht.sh/python/uppercase

- learn to maintain graphical tools, like pqiv and AutoHotKey. I think this is the harder of the two

If I want to convert a string to all caps inside of the browser, I can push F12 and then use the JavaScript console (it is also useful for doing simple calculations, and more; really, the web developer console is a feature I use a lot, despite not doing web development stuff). If I want to do so outside of the browser (I don't want to do everything in the browser; the outside stuff is often better), I can use the tr command.

If I want to deal with pictures, I always use external programs, such as ImageMagick or my own Farbfeld Utilities (although Farbfeld Utilities cannot currently read animations, so ImageMagick must be used instead).

It is possible to download web pages to run them locally, if there is some function you want to do on a web page which is less shady. I don't know which web pages are designed to do that, but you can write some if you want to.

So you want UNIX utilities in the web? Really?

Honestly it sounds like a fun project idea: make a page that can do random little manipulations on text for you in JavaScript. But really you'd probably be better off just bringing up a terminal and running some imagemagick commands or echo "turn this into caps" | dd conv=ucase

Well that’s what chrome apps were... These are being discontinued, though. Not sure what they are going to be replaced with.

But basically ChromeOs is what you describe...

Also observablehq.com is a collection of community-created javascript notebooks that run locally. You may be able to find all you need there...

I wrote a file sharing utility that works in the browser. If I want increased personal automation I put it into that tool. For something like convert a string to all caps open the browser developer tools and simply:

    myString.toUppercase()

I can't figure out the name or URL of it, but there is a really delightful in-browser HTML/JavaScript string toolbox out there on GitHub. I think it was developed at a U.S. Government agency, IIRC...