Bob at Wise Solutions emailed to remind me that the Wise Installation System has patching built in, and costs less than InstallShield plus vBuild.
He also pointed out that Wise for Windows Installer now has a ton of features for server setups: user account creation, IIS administration, and SQL Server administration… basically they implemented my entire wish list from working on the FogBUGZ 3.0 installer. Good work!
Some people on the forum expressed concern with the concept of distributing upgrade patches rather than complete copies of changed files. I can see why they are concerned, but I think they are underestimating the tools that are out there. These tools check the version of each file on the user’s machine and also compute a hash function to make sure that the file is not corrupted. If the file is corrupted, they automatically download the whole thing.
Using patching technology saves a lot of bandwidth, even for the first-time installer, because a lot of the bytes you’re distributing may be system files and runtimes that users already have. For example, we need to redistribute things like the Microsoft C Runtime (MSVCRT) which almost everyone already has, just because there may exist a few Windows machines in the wild which don’t have it. For consumer software which may well be downloaded over a modem, this makes a big difference.
For now, Michael convinced me to stick with the tried-and-true Inno Setup for the next release of CityDesk. The bandwidth savings don’t quite justify the effort of switching installers.