dwg drawing versions or dwg compare softwares?

[crushmaster]

1. Is it possible to save the drawing at a certain designing stage as a 'version'(not the AutoCAD versions) like in the MS word, if then I do some changes I can save in the next 'version’. And sometimes i may want to come back to the former idea; if I have 'saved' and 'closed' the file, I cannot recover the former version I passed by. How if deal with this problem now is to 'save as’, but sometimes there is more different ideas and 'save as' produce useless dwg files and not easy to manage too.

2. There are some commercial software like autodwg dwgsee.pro/compareDWG/VHCompare/OverCAD DWG Compare, who can compare different versions of dwg drawings and markup the differences between, is there any free one?

[ReMark]

The "save as" option is what we use or we isolate the geometry on its own layer and freeze it.

[mdbdesign]

Save as and give it different # or date, stage any time you finish part of it and after you can go back to past idea.

Add 2 - never used.

[cadvision]

Have a look at Rasterex's RxHighlight for file overlay and compare. www.rasterex.com