The issue didn’t affect everyone, only people who work with certain files in a variety of different applications.
A bit of background
Before Snow Leopard, a file would re-open inside the application that created it. If you wrote a web page in a text editor and saved it as HTML, next time you touched it, it would open in the same text editor.
This was done using “creator codes” – tiny snippets of information that some applications added to the files they created. In Snow Leopard, creator codes stopped working.
After Snow Leopard, saving as HTML meant that the default app for re-opening the same file became your browser – Safari, in most cases.
Most people wouldn’t be bothered by a change like this, but if you create web pages in text editors all day long, it could be troublesome.
It wasn’t confined to text editors and web pages either. For example, illustrators working in a variety of image editors found all their files opening in Preview by default. The system used to do the work of remembering which image editor you used for each file – with the change brought about by Snow Leopard, that job suddenly became the responsibility of the user.
What Magic Launch offers
Magic Launch is a small preference pane utility that intercepts your commands every time you open a file, and applies rules that you create.
Because it’s rule-based, it can be extremely flexible. Suddenly you have a great deal of control, if you devise your rules carefully.
For example, you could create a rule that opens all the HTML files inside a certain folder in your text editor. You can even specify that this should only happen if the editor is already open – if not, they’ll open in a browser.
The loss of creator codes only affected a minority of people, and as such a utility like Magic Launch will only be useful for that same minority. For $13, those people could find Magic Launch a very useful thing to have around.