A definitive method history database is one of the critical features required for Squeak 4.0

Rationale for a method history database

To authoritatively declare an image license-clean, we must have already proved that all contributions that make up that image. A pre-condition is that we know every contribution that went into the image. Thus, we need a list or database of all contributions that make up every method in the image.

Requirements

The database must list every contribution that can legally be considered "making up" the base image we choose to use, as well as a way to determine whether the contribution is explicitly licensed under either MIT or Apache 2 license. The following types of contributions are considered "copyrightable", and must be explicitly licensed under either MIT or Apache 2 license before the release can be considered "clean". See the LicenseAuditing page for details on what is clean or not

In order of quantity, the licensable contributions are:

1. Text in the image:
1. method source code
2. class comments
3. preference descriptions
4. other text?
2. Media within the image
1. Icons
2. Sounds
3. Fonts
3. What else?

A few things that are not copyrightable:

1. Class and method names
2. Class creation templates

Relevant Projects

By far the most troublesome of these is method source code. All other types of materials can be simply discarded from the system should they be license-unclean. Methods, however, must remain functional, and so must be rewritten. Thus, all history database projects primarilly address method source code:

• Maurice Rabb has been building a Squeak history database and a VersionBrowser tool to go with it. He says the history database can be working by late april. The current issue with it is the parser for very old squaek source files is not yet working.
• Craig Latta has a history and module mechanism expressly designed for this purpose, but it is not yet availible to the public. It is also not clear if it is yet populated
• Andrew Black is working on something like this. I have not yet asked about it's progress
• Andreas Raab made a package with all past squeak image files, change files, and source files in one place
• Colin Putney has said he would like to do this with Monticello 2
• Matthew Fulmer has said he would like to do this with DeltaStreams