RTF2PDF
RTF2PDF 1.0 is a cost-effective tool that enables editing of Rich Text Format (RTF) files and converting them into Portable Document Format (PDF) files.
Floating Point Solutions 
STL Editor
STL Editor is a powerful software for viewing, editing and printing Stereolithography (.STL) files. It is tailored to meet the needs of Rapid Prototyping machines and offers various advanced features to manipulate STL files.
STL Toolkit
STL Toolkit 1.0 provides accurate viewing and printing of STL files using Open GL graphics. It also allows conversion from and to various file formats.
XYZ Import for Rhino
The XYZ Import plug-in adds the capability for Rhino 2.0 to import graphical data from XYZ files.
HPGL Export for Rhino
HPGL Export for Rhino is a plug-in that enables Rhino 2.0 to export graphical data into HPGL Plot (PLT) files, expanding the software's capabilities.
XYZ Import for AutoCAD
XYZ Import for AutoCAD is a plug-in that adds the capability to import graphical data from XYZ files to AutoCAD 2000/2000i/2002.