Ubuntu and Kubuntu are BSD variants.
G++ and GCC are code compliers, these are how you used to install software. Basically if you didn't have one installed, you were kinda screwed. They used to come installed with every Linux / Unix / BSD flavor basically.
Most Linux / Unix / BSD software used to come in source files (the .c files). This was raw code and needed to be compiled to run. This is why GCC and G++ were generally included with all distro's. Also the windows equivalent of G++ would be Microsoft Visual Studio.
Webmin is also a server management application to easily configure your server. It's very useful as most servers do not have a GUI.
Also many flavors of Linux / BSD are not free
Apple OS X is a BSD OS and is not free.
Smoothwall corporate is a Linux firewall and is not free.
Red Hat is a desktop / server operating system and is not free.
Also my 3 favorite Linux / BSD distro's are these:
Apple OS X 10.4 (It's very flexible with the Apple SDK, I also run a network of Mac's)
Ubuntu (Great OS and once again great for servers and even desktop applications)
DD-WRT (It's a small linux based OS for use in broadcom processor based machines, such as the Linksys WRT54G)
I also first grew up using Mandrake even though I no longer use it.