Altiverb 6 for Mac OS X now runs on Intel Macs as well as RTAS/VST on Windows XP. Altiverb 6 Regular ($595) is the stereo, fully automatable VST/RTAS/MAS/AU reverb supporting up to 96kHz sample rates. Altiverb 6 XL ($995), the flagship product, adds Pro Tools TDM support, surround output up to 5.1, and sample rates up to 384kHz. The upgrade from Altiverb 5 to Altiverb 6 Regular is free, while the upgrade to XL costs $100 to $129 for existing Altiverb 5 HTDM users, depending on date of purchase.