A even more sharper knife!

They did it! Slic3r as a new version in the wild with the coolest features you can find, take look:

This is a very important update, grab it now and enjoy! I want to say thanks to the wonderful community that has been helping with feedback, early testing and nice ideas. A lot of people is involved in our open "quality assurance" process! 

New features:

• graphical interface for composing multiple objects in one single print (with tools for rotation, scaling etc.)
• new --merge switch to compose multiple object with auto-positioning from command line
• new option to randomize starting points across layers
• automatic detection of additional required perimeters for avoiding haps in domed/sloping objects (the perimeters settings means nowminimum perimeters as Slic3r could add more when needed)
• sequential printing: print a complete object, then move onto next one, with automatic collision detection
• ability to export STL files of composed plates, as well as a Splitcommand to turn multi-object files into individual objects
• we can read OBJ files now

Improvements:

• very large memory savings and speed boosts, allowing to process high-resolutions files without getting out of memory; also, the number of threads is customizable
• very improved surface quality due to new smoothing algorithms
• the GUI doesn't block while slicing and a Cancel button was added to stop the process
• hole perimeters are extruded in reverse order (from the outermost to the innermost) to get better overhangs
• a slight compensation is applied to avoid small hole shrinkage
• support material now uses honeycomb pattern (much work is still needed on support material)
• retract before changing tool for dual extrusion

Changes:

• SVG colors were inverted to better support DLP printing (next versions will carry more settings for SVG export)

Bugfixes:

• fixed some GUI memory leaks
• fixed some fatal errors
• fixed a bug causing high memory consumption when infilling every 2 or more layers
• some holes where filled
• some nearly-thin walls were discarded
• removed tiny dots/blobs that were generated sometimes
• bottom layer speed ratio wasn't taken into account when estimating layer time
• omit any G92 E0 when in relative mode

Slice and dice it!

Before printing your "hot from the oven" 3D model, you'll need to convert it in a language comprehensible to your 3D printer. A 3D printer is a CNC machine with a extruder as printing tool, so the logical step was adopting the same programming language used in the CNC, which is GCode.
Basically it tells to the machine which dots should connect... yes, all machines work like games you have played as a kid :)
Well, after this brief explanation, let's take a look at Slic3r, it's just one of many STL-to-GCode translators developed for 3D printing. At first glance it seams more user friendly than Skeinforge, but lacking some options/features, but I guess the main reason is the development team behind Skeinforge is the same as ReplicatorG, the Makerbot creators!
So, why should I use Slic3r? Well, take a look at RichRap wrote an impressive, let's call an essay, about Slic3r, take a look at it!