X2SW is the host software for RepRap 3D Printers.
Essentially it is a collection of the open source tools packaged together.
The included tools are modified for better interaction with dual extruding RepRap machines and each other.
You can find the downloads and additional information on the X2SW wiki pages.For those unfamiliar with the toolchain for RepRaps it consists of the slicer and the printer control interface software. The slicer is used for slicing the model into layers, preparing the toolhead path and generating commands for the printer. The printer control interface is used to manage the printer, setting it up and eventually getting the generated commands executed. The examples of the slicers are Slic3r and Skeinforge. The printer controller software examples are ReplicatorG, RepSnapper and Printrun.
The v1.1.0.1 of the X2SW software bundle combines two the most popular at the moment slicers (Slic3r & Skeinforge) and Printrun printer interfce software. It might be used in a binary form (self-contained, no need to install dependencies) or run from sources. The installer for Windows can do all the work to get a MS Windows PC ready for driving a RepRap 3D printer.
The x2Profiler tool included in the package helps to download the configuration files for the priner. The configuration files come from the online or local repository. They can be quite complex (especially Skinforge) and hard to manage at first. Storing them in the online repository allows for the experienced RepRap printer operators to share their profiles with the rest of the community.
The profiles can control many aspects of the printer operation, software UI and the features available. There are several example profiles for RepRap printers available at the moment. For example RepRap/X2/x2_0200 development profile enables all the dual exttruder features and both slicers. The old Skeinforge-only profile for Makerbot CupCake that has none of those capabilities doesn't expose any of those features. What is and isn't there is controled by the Printrun .pronsolerc file coming with the profile.
The bundle also contains the X2SW Merge tool capable of merging Skeinforge-generated "penultimate" g-code for two objects into one file for dual extruder printing of multi-color objects or objects made of different materials (see Printing for more details).