Any similar software for Linux?
Also, does it work over the internet/WAN (eg: server at home, checking up on it from work), or does it only work on an internal LAN/Ethernet network (eg: check server in attic, on laptop from livingroom couch below)?

ProDigit
Any similar software for Linux?
Also, does it work over the internet/WAN (eg: server at home, checking up on it from work), or does it only work on an internal LAN/Ethernet network (eg: check server in attic, on laptop from livingroom couch below)?

You would need to ask someone running Linux about software for Linux but as far as I know of no.
About the Network review Post #1 as it is all IP4 Based and you would have to setup your own network to allow access from the Internet.
You should contact harlam357 for your questions as well. https://groups.google.com/forum/#!forum/hfm-net

In general your ISP will block external access to your home network. Comcast/Xfinity will block it pretty effectively. Thats why many remote management utilities use relay servers. Fios does allow access remotely and I use a ubiquiti firewall with google dns for remote management and vpn access. Of course, this costs me about 20 a year for a domain name.

Just set this up on my laptop to monitor my 4 rigs and it was super easy since I'm only concerned with LAN connection
 
Downloaded newest version release on March 23rd, 2020 from https://github.com/harlam357/hfm-net