Hi all -

there's also the free XTrackCAD (now Open Source) available for

for free (and possibly others if you know what to do with the source code..).

XtrakCAD is nice. It's been my go to for a number of years.  But it's . . . 
1. Not as easy to use as SCARM
2. Has no built in 3D viewing capability. It interfaces with Rail3D through a 3rd party app, but there are bugs that limit it's usefulness (like track elevation)