TARL, the topic of this page is beyond obsolete, it is now defunct. The private individual, Steve Forget hosting and running the Trainzhaven website, at http://trainz.ws/tarl/ was doing so as a Greater Trainz Community service despite becoming relatively disinterested in regular Trainzing due to the time demands of a busy life. Unfortunately, after over three years of good citizenship Steve's site (TARL MK1) fell victim to a lightening strike, which also took out many of the backups. He and all contributors certainly earned all our thanks; especially valuable hard work was put in by Ianwoodmore, Bob Weber, Pencil42 and Spruce—who among others such as Pcas1986 are behind TARDIS (or parts of it), the current replacement.
Steve Forget advised the community he was pulling the plug on efforts to reconstitute the services (known as TARL MK2) August 17th, 2007, though there was an interval when some others tried to manage the load while he continued to host it.
Subsequently, TARL six years after TARL began brightening the day of Trainzers it was superseded by TARDIS (newset upgrade release is 3.7) scripts running on Asset-X, again community efforts spear-headed by a few determined Trainz lovers. There is a full description at this N3V Blog page.
To the new reader, it might be helpful to first understand that most errors can be fixed by edits to the config.txt file to fix up a path, or a file copy, transfer, or other easy edit. With a little experience the great majority can be fixed in a couple of minutes.
TARL begun back in the Trainz boom days before TRS2006 was the place to find out what to do to fix a config.txt file, or to find a missing asset. People could and would also post your fixes to a config.txt file for other people. TARL MK1, in the 3 years it was available, hosted some 8,000 repairs from ~500 authors' assets. Only one author declined to participate and his creations were regrettably excluded to the detriment of the Trainz Community in the opinion of many.
TARL was undergoing a thorough repair, upgrade and review back in 2007, but TARL MK2 never fully recovered the library amassed in TARL MK1. TARL was corrupted during a severe electrical storm in 2007. Many fixits were lost and some of the functionality. We hope to resume uploads by the end of 2008, but first we have to determine what's missing.