Of course, they are Linux....why do you ask?
In the classroom:
sparkylinux.org - a lightweight Debian OS....it's got Home, Base, and Gaming versions, depending on your need/platform (I like using old laptops instead of bleeding-edge)...the Home version is on my laptop in the classroom if anyone wants to "play" with it.
Zorin OS - VERY SLICK "Windows 7 like" interface. (another Ubuntu variant)....I have this on a laptop in the classroom if anyone wants to "play" with it.
For light-weight installs (like really old PCs or Netbooks):
www.lxle.net - very lightweight and great if you have an "older" pc (I use it on my old ASUS netbook for when I am on a public hotspot)..based on Ubuntu
- or -
Bodhi - VERY lightweight that can run on just about any platform out there.
- or -
Linux Lite - another Ubuntu variant that is lightweight and fast.
- or -
puppylinux.org - beware the lightweight killer chi-hua-hua.....as in a 100MB OS, (it's great for a bootable thumbdrive). I kinda like the MacPup variant of Precise Puppy. it's a little bigger (200MB) but still great for a thumbdrive. Both have "simplistic" interfaces so they would be good with kids or grandparents.
- Other flavors -
https://elementary.io/ - simple and elegant (it's based on ubuntu and would be great for pre-teen/teens or grandparents)
www.linuxmint.com - Great distro for Windows users
https://www.opensuse.org/ - openSUSE is a polished OS that's commonly used for desktops (like Government networks). I actually like the Gecko variant of it (much more noob-friendly).
https://kororaproject.org/ (FEDORA)
https://solus-project.com/ (formerly EVOLVE)
and (of course) http://www.ubuntu.com/
and still...for special purposes:
For SuperSecretSquirrelStuff that's reserved for people who don't want to be seen thru a PRISM:
https://tails.boum.org/
If you are going to have some Raspberry Pi, try Snappy:
http://developer.ubuntu.com/en/snappy/
If you are building a future computer nerd at the house (~kiddies K-4th grade):
https://www.sugarlabs.org/
If you are going to need an OS for a home server (please don't try a Hillary with it):
https://www.debian.org/
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Now....if you still want to know about what to do about replacing MS Office......
http://www.libreoffice.org/
and if you are concerned about not being able to use your CAC/PIV
https://militarycac.com/linux.htm
