LeoCAD uses LDraw Parts Library[0] as a set of "digitallego" bricks.

Also, highly recommend all AFOLs look on the "AWESOME LDraw"[1] — a list of useful digitallego resources (not only LDRaw-related, but also in other formats for various software other than LeoCAD).

> website has some pictures

Here is my latest screenshot[2,3] with my MOC "Micropolis Mallet Locomotive 0-8-8-0".[4,5]

[0] https://www.ldraw.org/

[1] https://git.io/digitallego

[2] https://i.imgur.com/tBZ2FCK.png

[3] https://twitter.com/app4soft/status/1371197528197193728

[4] https://twitter.com/app4soft/status/1217201295196663808

[5] https://twitter.com/app4soft/status/1234260641558548482