This module contains a grab-bag of unrelated misc. 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/