Almost none. Since The Tilery is a simple application, it usually doesn’t interfere with system extensions (INITs) or other applications. There are just a couple of exceptions.
Extensions and Memory
Some extensions (not many) like to borrow memory from running applications. If you use such extensions, you may have to give The Tilery more memory so that the extensions can use it.
Metrowerks CodeWarrior Debugger
There was a bad interaction between The Tilery 3.0 and the Metrowerks CodeWarrior Debugger, all versions up to at least CW6. The symptom was that the debugger could not trace the target code through a cross-segment jump on 68K Macs.
This has mostly been fixed in The Tilery 3.1 and later. It can still happen if the item being debugged has a custom icon. Since most applications have a proper BNDL instead of a custom icon, we don’t expect this to be a problem.
Metrowerks has also provided a fix (because the problem could also occur without The Tilery). The fix is in the DebuggerINIT 1.1.1 (note that’s the INIT, not the debugger itself), available from Metrowerks. See <http://www.metrowerks.com/> for more information.
If you are not a programmer, none of this will affect you.
Password Protection
Some screen-savers and security programs try to protect your Mac by refusing to allow any other applications to come forward until you type a password. Unfortunately, these programs are not really very secure. With some of them, you can use a hotspot to bring The Tilery forward anyway, almost completely defeating the “protection.”
The Tilery makes an effort to comply with such programs. AfterDark, Dark Side of the Mac, and some other screen savers have a way of advising other programs that password protection is in effect. The Tilery honors this advisory. It is safe to use The Tilery with these screen savers and with any other program which posts the same advisory.
For the technically inclined: the advisory is Gestalt selector ‘SAVR’, bit 4: set for password protection on, clear for off. Find a copy of “ScreenSaverGestalt.h”: the selector is named gestaltScreenSaverAttr and the bit is named gestaltSaverPasswordMode. If you are responsible for an application which attempts to lock out other programs via password protection, you should probably be using this mechanism.
