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Co-authored-by: Marcin Rataj <[email protected]>

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Co-authored-by: Marcin Rataj <[email protected]>

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Co-authored-by: Marcin Rataj <[email protected]>

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DEVELOPER-NOTES.md

@@ -7,8 +7,10 @@
     * [Build and run in Firefox](#build-and-run-in-firefox)
     * [Build and manually install in Chromium](#build-and-manually-install-in-chromium)
     * [Run build on file changes](#run-build-on-file-changes)
+* [Reproducible build in Docker](#reproducible-build-in-docker)
 * [Useful tasks](#useful-tasks)
 * [Other tips](#other-tips)
+* [Legacy Firefox (< 53) and XUL-compatible browsers](#legacy-firefox--53-and-xul-compatible-browsers)
 * [Using IPFS Companion on Firefox for Android](#using-ipfs-companion-on-firefox-for-android)
     * [Install Firefox for Android](#install-firefox-for-android)
     * [Install IPFS Companion](#install-ipfs-companion)
@@ -85,6 +87,23 @@ npm run watch # watch for new changes
 
 **Note:** `watch` is a blocking command, so one needs to run it in a different terminal than `firefox` or `chromium`. Press ctrl+c to stop it.
 
+
+## Reproducible build in Docker
+
+Want to ensure prebuilt bundle does not include any additional code?  
+Don't want to install JS dependencies such as NodeJS and yarn?  
+
+Do an isolated build inside of Docker!
+
+Run the following command for ending up
+with a built extension inside the `build/` directory:
+
+```sh
+npm run release-build
+```
+
+It is an alias for running `ci:build` script inside of immutable Docker image, which guarantees the same output on all platforms.
+
 ## Useful tasks
 
 Each `npm` task can run separately, but most of the time, `dev-build`, `test`, and `fix:lint` are all you need.
@@ -125,6 +144,11 @@ Release build shortcuts:
 - [Using localization in IPFS Companion](LOCALIZATION-NOTES.md) (running browsers with specific locale, etc)
 - [Testing persistent and restart features (Mozilla)](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Testing_persistent_and_restart_features)
 
+## Legacy Firefox (< 53) and XUL-compatible browsers
+
+Legacy versions `1.x.x` were based on currently deprecated Add-On SDK (Firefox-only).   
+While it is not maintained any more, one can inspect, build, and install it using codebase from [legacy-sdk](https://github.com/ipfs/ipfs-companion/tree/legacy-sdk) branch. For historical background on the rewrite, see [Issue #20: Move to WebExtensions](https://github.com/ipfs/ipfs-companion/issues/20).
+
 ## Using IPFS Companion on Firefox for Android
 
 Firefox for Android is capable of running some of the same extensions as the desktop version. This makes it very useful for experimenting with IPFS.