I’m thinking about using it alongside Blender and was wondering if it was possible to make something realistic with it. Rather than like a cartoon.
Like a Human, Or a table.
Thanks.
Warning: this is probably a rather biased piece of advice (what forum are we on 
so do take with a grain of salt…
Over the years, I’ve observed the glacial rate of evolution of K-3D, and have tried various versions along the way. My experience with it has been very much less than impressed, with each and every version crashing on one or other critical operation (one version would even cause my system to hard reboot on when starting).
Current versions are relatively “more stable”, though I’d bet that Blender 2.5 alpha versions were probably more usable, with the current versions (since 0.6 or so) having adopted a blotched attempt at a Maya-esque UI that layouts out tools in ways totally unconstructive to any form of efficient workflow (case in point - check out some of the very long menus of ‘nodes’, sorted not by commonly-used functionality, type of functionality, but just a very long named-based alphabetical list dump with no facilities to narrow down this view via search or other mechanisms).
Another point worth noting is that K-3D is first and foremost a playground for the authors to play around with Software Engineering methods, with the emphasis on software architecture (and “cleanliness”, probably based on their current ideals of best practice at the time) rather than the usability of the software product for any actual 3D work.
Just be aware of these points 
Now a days many website offer K-3D software as free. You can run it on your choice of platform. You can also share it with your friends. And also as I heared that all of the K-3D source code is available under the GNU General Public License. Most interesting thing is that I have tried K-3D again last night. And I like all of its features.