I think we should learn very carefully from Gemstone migration experiences to develop our Smalltalk systems *upfront* with migration in mind. Just see all recent (or less recent) examples: MC2 seems too radical to be easily migrated from MC1 and obviously designed without migration in mind, SqueakSource as well, SS3 too? Such systems just don't have any chance to be accepted and old systems will live and live instead. So, don't develop just a "cool" stuff, take some time to think about migration and long-term maintenance issues as well, if you like that your system will be accepted with the community to your glory :) Janko On 27. 04. 2011 22:16, Dale Henrichs wrote:
Since you mention GemStone:)
We have customers who have migrated repositories created 10+ years ago with our 32 bit product to the latest current version of our 64 bit product.
We have changed our Smalltalk class-library over the years and customers have had to upgrade their own class libraries if they chose to continue taking advantage of our newer releases ... then there are some who have chosen not to migrate: I think there are still production applications running GemStone on a version 20 years old:) ... as long as their hardware holds out they are fine:)
Production customers don't tend to move very fast in upgrading their hardware and software so we end up supporting older versions of oSes for quite awhile...But when the os vendor announces and end of life of an os, it becomes difficult for us to continue to support that version...
For the older versions we backport critical bugfixes to the older versions as long as their are active customers (read paying maintenance dollars) using the older versions.
Dale
-- Janko Mivšek Aida/Web Smalltalk Web Application Server http://www.aidaweb.si