Apps for BSD?

Where do you find apps for BSD? Does BSD have a port of KDE and GNOME? If I have the source of a Linux app, will I be able to compile and run that program in BSD? Or can Linux binaries run in BSD? Are there as many apps for BSD as there is for Linux?

*BSD can run X with KDE, Gnome, or any other window manager you wish to use. Many Linux applications are available in the ports collection, and there is Linux compatability layer if your favorite Linux app isn't included. There are more apps for *BSD than Linux, because *BSD can run Linux apps and Linux cannot run *BSD apps. For more information, you need to be more specific as to whether you are using FreeBSD, NetBSD, OpenBSD, or some other derrivitave.

Which BSD is best to try as a home desktop OS? I've heard BSD is so much better than Linux, but I don't know anything about it.

It's a matter of opinion, but there are a few facts to help you choose the best for you.
FreeBSD and NetBSD have both been around since 1993, with their roots going back to Cal State Berkeley in the 1970's. OpenBSD split off from NetBSD in 1995. Although there are not any major differences between the different types, NetBSD runs on many more platforms than OpenBSD or FreeBSD, and they pride themselves upon that fact. OpenBSD, on the other hand, boasts that there has only been one security hole in the default install since its founding. FreeBSD is probably the most-used type for Intel and compatible hardware. It's really up to you. Since there are a lot fewer options than with Linux, it won't hurt to try out all three. For more info, see this thread

Which one would be best for an AMD Duron 900 Mhz, 256 MB Ram, 15 GB HD. Most of the hardware is about two years old.

What type of development system is included in FreBSD?

FreeBSD would be a good choice for you to try. it has the most applications available in the ports systems, over 9000 applications and still growing.

What type of development system is included in FreeBSD?