I use brew on macOS but didn’t realized that they added support for Linux some time ago 
- thanks for the hint!
And yes, it will work on Endless OS, but it involves a few extra steps. I just installed it using the following procedure:
Install curl
We need curl, so we install a static binary build of it:
sudo mkdir -p /usr/local/bin
sudo wget -O /usr/local/bin/curl https://github.com/moparisthebest/static-curl/releases/latest/download/curl-amd64
sudo chmod +x /usr/local/bin/curl
Install brew
… it’s installed with the same command as given on their homepage, but you have to make sure to press Ctrl-D when asked, as we want a per-user local installation:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
when the installation has finished, you need to put some environment variables into your shells startup script:
echo PATH=${PATH}:~/.linuxbrew/bin >> ~/.bashrc
export HOMEBREW_CURL_PATH=/usr/local/bin/curl >> ~/.bashrc
export MANPATH=${MANPATH}:~/.linuxbrew/share/man >> ~/.bashrc
Use brew
Example, install the tool sponge
brew install sponge