Hi all, just to inform you:

The XTrackCAD Free Layout Software has been updated and released for download in May 2015 in Version 4.2.0:
http://www.xtrkcad.org (Download, Wiki and Introduction)

It is a basic 2D layout planning software. XTrackCAD is available under GNU General Public License v2 for Windows, LINUX and OSX. It comes with a broad range of definitions for track components and accessories. The following Maerklin track parameter files amended and newly added to the recently updated download package might be of special interest for this forum:

Maerklin M-Gleis & Signale HO-Scale (mrkhomde.xtp): semaphore and lights signals, Maerklin signal symbols (corresponding to Maerklin track plans)
Maerklin Modellgleis HO-Scale (mrkholde.xtp): Maerklin Model Track 3900 and 3800 (asked for in https://www.marklin-users.net/forum/posts/t17385-Model-Tracks-3900-and-3800---Modellgleise-3900-und-3800):

Also indluded are:
Märklin 1-Scale Turnouts (mrkln1.xtp)
Märklin C-Gleis HO-Scale (mrklnhoc-de.xtp)
Märklin C-Track HO-Scale (mrklnhoc.xtp)
Märklin K-Track HO-Scale (mrklnhok.xtp)
Märklin M-Track HO-Scale (mrklnhom.xtp)
Märklin Z-Scale Turnouts (mrklnz.xtp)

All track parameter files can be edited and amended according to your personal needs. More can be found in the file area of the XTrackCAD mailing list at http://groups.yahoo.com/group/xtrkcad/. You can ask special questions there, in case you don't find the answer to your problem in the wiki or in the group conversation.

Perhaps you find XTrackCAD a suitable solution for your layout planning. I'm vrey happy with its basic functioning and the ability to really control what it does.

Cheers Jo