Concord/Corina replacements for Linux

Good afternoon all, and thanks to everyone who responded to my previous
 questions about openbabel and descriptor code.  I have one other
 question about software that has come up.  Can anyone recommend a
 program that can generate 3D structures of any quality of all from 2D
 representations?  I know that Concord and Corina can do this, but I am
 doing this for my own education/edification and would rather not blow
 the rent money on this project.  I'm hoping to take some data I have
 pulled from various publications on my laptop on a train trip and putter
 with it en route, so a web-based tool is less than ideal.  If anyone has
 any suggestions, I would be most appreciative.