I really like Syncthing, Nextcloud, Forgejo and Mailcow to collaborate with colleagues.
Kimai allows me to track hours and get paid.
Barrier allows me to use several computers at once.
Xen Orchestra is pretty much on par with VMWare stuff and way cheaper.
What other awesome software does allow you to work more efficiently in a business context and stays out of your way?
In my case with lightweight office suite usage, the integration of onlyoffice with nextcloud is awesome
No nextcloud client required and it can access to all the office documents on your nextcloud
Although OnlyOffice is not “fully” open source, as you can’t compile it without the secret proprietary bits