In Chapter 19, we started Instruments from Xcode by selecting Run > Start with Performance Tool and selecting an Instruments template. At least as often, you'll just launch the Instruments application from the /Developer/Applications directory.
When you start it, Instruments automatically opens a document (called a trace document) and displays a sheet offering you a choice of templates populated with instruments for common tasks (see Figure 26.1). You can find a complete list of the templates Apple provides in the section "The Templates" later in this chapter.
Figure 26.1 When you create a new trace document in Instruments, it shows you an empty document and a sheet for choosing among templates prepopulated with instruments for common tasks.