Up until OS X version 10.3, application switching in OS X has been poor. To switch the active application in 10.2, you hit Command-Tab and a highlighted dock icon told you which application was selected. It worked, but it had problems. The biggest of which occurred when open applications were separated by several unopened applications on the dock. When this happened, the highlight skipped across these unopened applications in a seemingly unpredictable manner because almost no one could remember exactly which applications were open and which applications where closed.
10.3 fixes this problem by introducing a new application switcher, very similar to the Windows application switcher and also very similar to LiteSwitch X, an application switcher developed by Proteron.
Samuel Caughron, developer of Proteron’s LiteSwitch X, has written an open memo to Apple regarding 10.3’s new application switcher. He claims that a developer at Proteron first conceived of it and that Apple should recognize this. As John Gruber has already stated, both of these claims are absurd. Almost every developer knows that Windows has featured an application switcher since version 3. LiteSwitch X was by no means an original idea. Expecting Apple to recognize a fallacy further contributes to Caughron’s ignorance.
If Caughron were smarter, he wouldn’t have said anything about original ideas or Apple’s failure to recognize Proteron. What he should have done was simply congratulate Apple on implementing a new application switcher and point out that Proteron offers an application that does pretty much the same thing as 10.3’s application switcher, but it does it better. Because LiteSwitch X does do it better.
To summarize: good job Apple, bad move Caughron, download LiteSwitch X (it overrides 10.3’s application switcher when installed).