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+# Miscellaneous Modules
+
+This module contains a grab-bag of unrelated miscellaneous libraries, *none* of
+which is an extension.
+
+## Application Online Update Checking
+
+When we start LO, first `InitUpdateCheckJobThread` is created, via
+`UpdateCheckJob::execute()` (from `extensions/source/update/check/updatecheckjob.cxx`),
+as a reaction to a `onFirstVisibleTask` event. It waits 25 seconds (so that it
+does not interfere with the startup itself), and then calls
+`UpdateCheck::initialize()` (from `extensions/source/update/check/updatecheck.cxx`).
+
+This creates one more thread, `UpdateCheckThread`, that regularly checks whether
+we have reached the time when we should ask for the update.  If yes, asks for
+that, and shows the download button in the menu (if the new update is
+available).
+
+## OLE Automation Bridge
+
+A bridge between "OLE automation" and UNO, so you can use UNO services
+from JScript, VBScript, etc.
+
+<https://www.openoffice.org/udk/common/man/spec/ole_bridge.html>
+
+See `udkapi/com/sun/star/bridge/oleautomation/ApplicationRegistration.idl`
+
+This is initialized in `Desktop::Main()` in `Desktop::OpenClients_Impl()`
+by creating the service `com.sun.star.bridge.OleApplicationRegistration`,
+which is implemented by `OleServer_Impl`.
+
+See `extensions/source/ole/`
+
+## ActiveX Control
+
+This allows embedding LO into a Win32 application as an ActiveX control.
+
+See `extensions/source/activex/`
+
+## Spotlight Provider
+
+On macOS, this allows indexing ODF documents with Spotlight.
+
+See `extensions/source/macosx/spotlight/`
+
+## Scanner Support
+
+You can scan from LibreOffice, using platform specific backends like TWAIN/SANE.
+
+See `extensions/source/scanner/`
+