Not sure if this is by any means useful, but here you go:
You can run more than one instance of the same Cocoa app, for example two Clock apps running under the different process id, from the command line. It is pretty simple to do:
Using Finder, navigate to the app you want to run
Control-click, then select the 'Show Package Contents' item
Open ./Contents/MacOS folder. There is usually only one executable file.
Drag and drop the file on the terminal window. This prints a path to the file.
Put '&' at the end of the path and type return
Repeat 5 and 6
Now, you have two processes of the app.
Caveat: GUI apps are not intended to be executed by this way. If more than one instances are running, they access the same configuration files, e.g. a preferences file. So, there is a chance to corrupt these files. Do it at your own risk and just for entertainment.
The small icon in the Get Info window in OS X is useful as an application launcher, too. If you have an application selected in the Get Info window, a double-click on the icon will launch that app. A double-click on a document icon will launch that document's associated application. Finally, a double-click on a folder icon will open a Finder view of that folder.
As always, you can still single-click and cut-and-paste custom icons.
I recently went through hell to get OS X installed on my Dual G4 450. Having read most of the public message boards (macfixit, macnn, apple, macaddict etc) looking for answers, I thought I would impart some of my hard won knowledge to the greater readership of macosxhints.
If you are getting kernel panics or installer error messages that say "could not write file to disk/archive" during your install, you may have problems with RAM or 3rd party devices.
For more great installation tips from Yuri, read the rest of the article!
There is a great utility for OS 9.1 from Clarkwood Software called Peek-a-Boo (PaB). This is the best utility I've seen for monitoring processes that run inside Classic. When xload or ProcessViewer shows that something has pegged the CPU, run PaB and it will tell you WHICH process within Classic is hung, and often/usually succeed in letting you kill the offending process using PaB.
You can read about and download PaB from Clarkwood Software's Peek-a-Boo page.
All Cocoa apps respond to familiar commandline controls. This is what I mean, go into a Cocoa application (Omniweb, TextEdit, anything that is not Carbon or Classic) and click on any text field.
Type some random stuff, then press CTRL-A, it will bring the cursor to the beginning of that line, which is a common control in UNIX command lines. [Note: CTRL = the control key]
Read the rest of the article if you'd like to learn a number of other keyboard shortcuts for text editing in Cocoa apps.
[Editor's note: This isn't really just for UNIX geeks. How many times have you wanted a quick way to navigate around a text box without using the mouse?! Learn a few of these shortcuts, and free yourself from the mouse!]
If you have a folder in your Finder toolbar, hold option and click to open that folder in a new window and close the old window. Clicking without option simply opens that folder in the existing window. Strangely, it seems to switch to icon view regardless of the view mode from which you click [editor - not on my machine; it seems random!]. If you command-click the folder, it opens in a new window without closing the old one.
Application icons that have been added to the toolbar can be used to switch to the given app, saving you a bit of time and mousing down to the dock to switch. Drag-and-drop apps (such as Stuffit Expander) can have things dropped on them on the toolbar.
As I noticed my system time slowly drifting away from my WWV radio-clock time, I decided to re-check Date & Time settings and found that time wasn't being set automatically. Here's one way to keep your clock synchronized.
Open the Date & Time control panel, and go to the Network Time tab. Make sure Network Time synchronization is OFF (click the button to stop if necessary). Select MANUALLY, and enter an IP address for a Network Time Server (NTS) into the NTP field. There's a listing of appropriate servers at: