TeachBooks Versioning

TeachBooks Versioning#

This page reuses adapted CC BY 3.0 content from Tom Preston-Werner Preston-Werner (2025). Find out more here.

Inspired by versioning systems in software management (i.e. semantic and CalVer versioning) TeachBooks suggests a versioning guideline in which the version number tells the reader about the impact of the change. This might more suitable for your online books than the more traditional way of versioning paper books (version 1, 2, etc.), because of the amount of edits which online books allow. We recommend TeachBooks versioning, which comes in two flavors:

  1. academic_year.additions.errata versioning for books tailed-made for courses in which content is added / adapted during the course and might be restructured extensively every year while remaining to be available in the original form.

  2. major.errata versioning for books which are more stable over years, in which big changes are covered only by the version number.

We have come up with guidelines how to use the two TeachBooks-versioning options (adapted from (Preston-Werner, 2025)):

  1. A normal version number MUST take the form academic_year.additions.errata where academic_year is the academic year in which the book is used, and additions, and errata are non-negative integers, and MUST NOT contain leading zeroes. Each element MUST increase numerically. For instance: 2025.9.0 -> 2025.10.0 -> 2025.11.0

  2. Once a versioned book has been released, the contents of that version MUST NOT be modified. Any modifications MUST be released as a new version.

  3. Errata versions MUST be incremented if a small change is made which should be communicated to the reader in both the source code and in the book itself. If the small change is not crucial (like a simple typo), you might consider not defining it as a new version but combining it with other changes in the next errata or additions version.

  4. Additions version MUST be incremented if an addition is made to the book. It MUST be communicated in both the source code and in the book itself. It MAY include errata level changes. The errata version MUST be reset to 0 when the addition version is incremented.

  5. Academic year version MUST be incremented if a fresh book is started for which additions will follow later. It MUST be communicated in both the source code and in the book itself. Additions and errata versions MUST be reset to 0 when academic version is incremented.

  6. Precedence refers to how versions are compared to each other when ordered.

    1. Precedence MUST be calculated by separating the version into academic year, additions and errata identifiers in that order.

    2. Precedence is determined by the first difference when comparing each of these identifiers from left to right as follows: Academic year, additions and errata versions are always compared numerically. Example: 2024.0.0 < 2025.0.0 < 2025.1.0 < 2025.1.1.

  7. The way in which the version number is incremented after the initial release should be explained in the README of the source code and in the book itself.

An example can be seen in the source repository of the Engineering Systems Optimization book showing tags for different versions.

  1. A normal version number MUST take the form major.errata where major, and errata are non-negative integers, and MUST NOT contain leading zeroes. Each element MUST increase numerically. For instance: 9.0 -> 10.0 -> 11.0

  2. Once a versioned book has been released, the contents of that version MUST NOT be modified. Any modifications MUST be released as a new version.

  3. Errata versions MUST be incremented if a small change is made which should be communicated to the reader in both the source code and in the book itself. If the small change is not crucial (like a simple typo), you might consider not defining it as a new version but combining it with other changes in the next major version.

  4. Major versions MUST be incremented if a substantial restructure or additions is made. It MUST be communicated in both the source code and in the book itself. Errata versions MUST be reset to 0 when the major version is incremented.

  5. Precedence refers to how versions are compared to each other when ordered.

    1. Precedence MUST be calculated by separating the version into major and errata identifiers in that order.

    2. Precedence is determined by the first difference when comparing each of these identifiers from left to right as follows: major and errata versions are always compared numerically. Example: 1.0 < 2.0 < 2.1.

  6. The way in which the version number is incremented after the initial release should be explained in the README of the source code and in the book itself.

Read TeachBooks versioning with changelog on how to combine this with a changelog, tags and releases!