ACPI in Linux -- Myths vs. Reality (OLS 2007)
ACPI in Linux -- Architecture, Advances, and Challenges (OLS 2005)
The State of ACPI in the Linux Kernel (OLS 2004)
The previous Linux ACPI home page
http://acpi.sourceforge.net/ will continue to host a DSDT database, and will continue to document the deprecated /proc/acpi interface used in older kernels.