MeshMixer is a 3D design and modeling tool for 3D printing or scanning, supported by Autodesk (acquired 2011). While not discontinued, the product will not receive updates and Autodesk states they intend to include all functionality in updates of Fusion 360.
Autodesk MeshMixer is best for repairing STL files and basic modifications toward 3D printing. It is excellent for hollowing out models and adding escape holes for SLA printing or lost-wax casting. Its CSG (Boolean) functions to combine different meshes are good too and seldom cause the program to crash. There is even an integrated algorithm to optimize the layout of multiple files on a print bed in case of small-batch production. Autodesk MeshMixer's sculpting tools are there yet limited and there are a few better alternatives. Best of all, it is completely free.
The remeshing tool needs to be faster, as in some cases it takes up to a day of waiting time.
The sculpting tools need the addition of a proper brush for creating sharp creases and ridges.
The standard shape library is rather limited. It would be nice to have this connected to online repositories such as Thingiverse, MyMiniFactory, or Cults3D.
Using Blender for STL file preparation is like swatting a mosquito with a wrecking ball, plus its boolean functionalities can be glitchy. ZBrushCoreMini proved too limiting as a sculpting tool, but so did Autodesk MeshMixer, so I am sticking to Sculptris. Materialise Magics and Netfabb are somewhat better at STL file repair and offer more advanced functionalities. But Magics does not remesh as well and Autodesk MeshMixer is far more compact and faster than Netfabb, so remains my weapon of choice.