|Type:||3D model (volume/mesh)|
|Software:||e.g. Onshape, Tinkercad, Meshmixer;|
export from many others
|Machines:||3D printers (upon slicing)|
|Repositories:||check out this list or STLfinder.com|
STL files are imported in a slicing software like Cura before printing.
The majority of 3D printing designs are still shared as STL on Thingiverse, but after Makerbot, the company behind Thingiverse, was bought by Stratasys and changed the terms of service, many artists decided to leave Thingiverse and use other STL sharing platforms instead.