diff --git a/README.md b/README.md
index 56222041..f2171979 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ See [Contributing](.github/CONTRIBUTING.md).
 - [Automation](#automation)
 - [Blogging Platforms](#blogging-platforms)
 - [Bookmarks & Link Sharing](#bookmarks--link-sharing)
-- [Calendar and Address Books](#calendar-and-address-books)
+- [Calendaring and Contacts Management](#calendaring-and-contacts-management)
 - [Communication systems](#communication-systems)
   - [Custom communication systems](#custom-communication-systems)
   - [Email](#email)
@@ -192,21 +192,30 @@ See also [Static Site Generators](#static-site-generators), [Content Management
 - [Shaarli](https://github.com/shaarli/Shaarli) - Personal, minimalist, super-fast, no-database bookmarking and link sharing platform. ([Demo](https://demo.shaarli.org)) `Zlib` `PHP`
 - [unmark](https://github.com/plainmade/unmark) - An open source to do app for links. `MIT` `PHP`
 
-## Calendar and Address Books
+## Calendaring and Contacts Management
 
 **[`^        back to top        ^`](#)**
 
 Some [Groupware](#groupware) solutions also feature calendar/address book editing and synchronization.
 
+See https://en.wikipedia.org/wiki/Comparison_of_CalDAV_and_CardDAV_implementations
+
+_CalDAV or CardDAV servers_
+
+- [Baïkal](http://sabre.io/baikal/) - Lightweight CalDAV and CardDAV server based on sabre/dav. ([Source Code](https://github.com/sabre-io/Baikal)) `GPL-3.0` `PHP`
+- [CalendarServer](https://www.calendarserver.org/) - Apple, Inc.'s standards-compliant server implementing the CalDAV and CardDAV protocols shipped with macOS Server. ([Source Code](https://github.com/apple/ccs-calendarserver)) `Apache-2.0` `Python`
+- [calypso](https://keithp.com/calypso/) - Python-based CalDAV and CardDAV server, forked from Radicale. ([Source Code](https://keithp.com/git/calypso.git)) `GPL-3.0` `Python`
+- [DAViCal](https://www.davical.org/) - Server for calendar sharing (CalDAV) that uses a PostgreSQL database as a data store. ([Source Code](https://gitlab.com/davical-project/davical)) `MIT` `PHP`
+- [EteSync Server](https://www.etesync.com) - End-to-end encrypted and journaled personal information server supporting calendar and contact data, offering its own clients. ([Source Code](https://github.com/etesync/server-skeleton)) `AGPL-3.0` `Python/Django`
+- [Radicale](http://radicale.org/) - Simple calendar and contact server with extremely low administrative overhead. ([Source Code](https://github.com/Kozea/Radicale)) `GPL-3.0` `Python`
+- [SabreDAV](http://sabre.io/) - Open source CardDAV, CalDAV, and WebDAV framework and server. ([Source Code](https://github.com/sabre-io/dav)) `MIT` `PHP`
+
+_CalDAV or CardDAV clients._
+
 - [AgenDAV](http://agendav.org/) - Multilanguage CalDAV web client with a rich AJAX interface and shared calendars support. ([Source Code](https://github.com/agendav/agendav)) `GPL-3.0` `PHP`
-- [Baïkal](http://baikal-server.com/) - Lightweight CalDAV+CardDAV server. ([Source Code](https://github.com/fruux/Baikal)) `GPL-3.0` `PHP`
-- [CalendarServer](http://trac.calendarserver.org/) - A standards-compliant server implementing the CalDAV and CardDAV protocols. `Apache-2.0` `Python`
-- [calypso](http://keithp.com/calypso/) - A python-based CalDAV/CardDAV server. ([Source Code](https://keithp.com/git/calypso.git)) `GPL-3.0` `Python`
-- [DAViCal](http://www.davical.org/) - A server for calendar sharing (CalDAV). ([Source Code](https://gitlab.com/davical-project/davical)) `MIT` `PHP`
-- [EteSync](https://www.etesync.com) - Secure, end-to-end encrypted and journaled personal information cloud synchronization for Android and the desktop. Currently contacts and calendars, with more on the way. ([Source Code](https://github.com/etesync/)) `AGPL-3.0` `Python/Django`
-- [Radicale](http://radicale.org/) - A Simple Calendar and Contact Server. ([Source Code](https://github.com/Kozea/Radicale)) `GPL-3.0` `Python`
-- [sabre/dav](http://sabre.io/) - A open source CardDAV, CalDAV and WebDAV server. ([Source Code](https://github.com/fruux/sabre-dav)) `MIT` `PHP`
+- [DAVDroid](https://www.davdroid.com/) - Open-source CalDAV/CardDAV suite and sync app for Android. ([Source Code](https://gitlab.com/bitfireAT/davdroid)) `GPL-3.0` `Java`
 - [InfCloud](https://www.inf-it.com/open-source/clients/infcloud/) - An open source CalDAV/CardDAV web client implementation. ([Demo](https://www.inf-it.com/infcloud/), [Source Code](https://www.inf-it.com/InfCloud_0.13.1.zip)) `AGPL-3.0` `Javascript`
+- [EteSync Web](https://www.etesync.com/faq/#web-client) - EteSync's official Web-based client (i.e., their Web app). ([Demo](https://client.etesync.com/), [Source Code](https://github.com/etesync/etesync-web)) `AGPL-3.0` `TypeScript`
 
 ## Communication systems