I think sorting them numerically is nicer than purely alphabetical sort, but I'd be cautions on switching the order from newer -> older to older -> newer -- I think there's a few places that do things like solc-select versions | head -1 to grab the latest release number.

Ignore my previous concern, I'm not finding the script calls I thought we had on places 🤷 and worst case it should not take much to fix them.

Regarding ordering by older -> newer instead of newer -> older, I picked this ordering to match how nvm sorts. I checked some other tools and it looks like this is the prevailing convention:

rvm:

$ rvm list known
# MRI Rubies
[ruby-]1.8.6[-p420]
[ruby-]1.8.7[-head] # security released on head
[ruby-]1.9.1[-p431]
[ruby-]1.9.2[-p330]
[ruby-]1.9.3[-p551]
[ruby-]2.0.0[-p648]
[ruby-]2.1[.10]
[ruby-]2.2[.10]
[ruby-]2.3[.8]
[ruby-]2.4[.10]
[ruby-]2.5[.8]
[ruby-]2.6[.6]
[ruby-]2.7[.2]
[ruby-]3[.0.0]

(...)

gvm:

$ gvm listall

gvm gos (available)

   go1
   go1.0.1
   go1.0.2
   go1.0.3
   go1.1
   go1.1rc2
   go1.1rc3
   go1.1.1
   go1.1.2
   go1.2
   go1.2rc2
   go1.2rc3
   go1.2rc4
   go1.2rc5
   go1.2.1
   go1.2.2
   go1.3
   go1.3beta1
   go1.3beta2
   go1.3rc1
   go1.3rc2
   go1.3.1
   go1.3.2
   go1.3.3
   go1.4
   go1.4beta1
   go1.4rc1
   go1.4rc2
   go1.4.1
   go1.4.2
   go1.4.3
   go1.5

(...)

Also note that solc-select versions | head -1 would not output the latest release using the current sort either, for example if I have all ^0.8.0 versions installed then solc-select versions currently outputs:

$ solc-select versions
0.8.9
0.8.8
0.8.7
0.8.6
0.8.5
0.8.4
0.8.3
0.8.2
0.8.17 (current, set by /home/ubuntu/.solc-select/global-version)
0.8.16
0.8.15
0.8.14
0.8.13
0.8.12
0.8.11
0.8.10
0.8.1
0.8.0

So it would not output the latest version:

$ solc-select versions | head -1
0.8.9

This gave me another idea though. It would be really useful for solc-select install and solc-select use to accept the argument latest as an alias for the latest Solidity version (similar to how solc-select install all can be used as an alias to install all versions). I created #138 to track this idea.

Rebased the commit against the latest updates in dev, and also amended to sort get_installable_versions():

-           for version in get_installable_versions():
+           for version in sorted(get_installable_versions(), key=lambda v: [int(s) for s in v.split(".")]):

Merged the dev branch, resolved some conflicts, and extracted the sorting logic into its own function. If tests pass I think this would be good to go 👍 thanks for the PR and the patience @ardislu!