3D printing on Mac OS X

[LambdaFF]

First off, thanks for that reply. I'm a complete NOOB so do I understand correctly that those S3D and Cura programs just eat STL files which I can create with any CAD program and feed the slices to the printer?

A slicer program cuts the STL file into layers to generate a gcode file (toolpaths and temperature control). Then you can either feed the gcode to the machine on a card or control the machine with something like repetier.
S3D does the slicing and the control. I don't know cura, should be easy to check.

Second, the more I read abut these printers the more confused I get about firmware. Let's say that I buy one of the printers on that list (I took a look at the Velleman K8200/K8400 for example) would that printer be plug-and-play with either S3D or Cura or would I have to upload different custom firmware for each different programs I use?

The firmware is what is in the controler in the printer and is specific to the printer due to its geometry and components. S3D, Cura, well -any slicer- can handle a variety of firmwares but not all of them, thus the compatibility list. Usually the OEM will tell you what is recommended with his machine. The rep rap firmwares have been used and personalized a lot by each OEM, but overall Marlin is frequent (I think), thus the large compatibility list for Cura and S3D.

[kristjanr]

The firmware is what is in the controler in the printer and is specific to the printer due to its geometry and components. S3D, Cura, well -any slicer- can handle a variety of firmwares but not all of them, thus the compatibility list. Usually the OEM will tell you what is recommended with his machine. The rep rap firmwares have been used and personalized a lot by each OEM, but overall Marlin is frequent (I think), thus the large compatibility list for Cura and S3D.

So S3D would work with whatever OEM firmware the K8200/8400 or whatever other printer in the compatibility list ships with?