Current Situation: I'm currently searching a good installer system (e.g. Nullsoft NSIS) with a strong focus on upgrades functionality. I'm developing some kind of programming IDE which is currently in Alpha / Beta status - therefore i need to deliver quite a lot of upgrades to my customers. My aim is to only transfer the nessassary files (e.g. 400 MB project, only the exe changed ==> Only the exe is packed in the installer). If you have version 10 and need to upgrade to version 15, the same method should be applied. This should be realized over the last ~5 updates (NO dynamic creation of installation packages on the server but static creation of several installation files for each update. So if i want to "delete upgrade" the last 5 versions, I need 1 full installation + 1 + 2 + 3 + 4 = 11 files for each version on the server - which is okay for me).
At the moment I'm using Nullsoft NSIS Installer System - and I've even written a small "generation script", which computes all changed files and generates a corresponding upgrade NSI file from that. But that's 1) a real pain, 2) error-prone and 3) not very let's say "developer friendly".
Question 1: Is there a low-cost / open source alternative installer which allows to realize small-sized upgrades / has a focus on long time upgrade projects?
Question 2: As a completly different approach to the static installer files: Are there well known open source / low cost dynamic server systems - which generate the delta files on the fly (without blowing up the server)?
NSIS has the VPatch plugin...