Installer and Updater for a python desktop application
There is a suite of tools from the cloudmatrix guys that addresses that problem.
esky is an auto-update framework for frozen apps that is compatible with the common python "packaging" frameworks. signedimp tries to ensure that apps are not modified after they are signed, and to minimize invasive Windows UAC dialogs. myppy aims to insulate you from base library incompatibility issues on Linux eg installing on distributions with different gcc and libc versions. The whole set can be seen on github here.
The video and slides from this year's PyCon are here: http://lanyrd.com/2012/pycon/spckh/
WiX (Windows Installer XML toolset) is an open source project for an MSI authoring tool.
Part of the project is ClickThrough, a set of add-on tools, including a tool to automatically detect available updates (via an RSS feed), notify users and install the update.
As you can read here:
The Windows Installer Xml (WiX) toolset is composed of a compiler, a linker, a lib tool and a decompiler. It generates MSI and MSM files from XML input. It doesn't include a GUI frontend to create the project files, but there are a couple of projects that plan to fill this gap. Votive, which is part of the WiX project, is a Visual Studio extension. It allows you to create "WiX projects" that act like any other project in a VS solution. WiX was created by Rob Mensching, a Microsoft employee and former member of the MSI team, in his free time and released as open source. It is used by several teams inside Microsoft to create their setups.
I'm working on a project that you may find useful.