Address Book Server allows you to share your contacts and calendar events with others connected to your network or over the Internet. Each participant synchronizes their contacts with the server hosted on your own system. Address Book Server supports the full Address Book and iCal schema. The server also provides a friendly Web interface and an iPhone client which let you access your contact details remotely.
Googsystray is a system tray app for Google Voice, GMail, Google Calendar, Google Reader, and Google Docs. It lets you keep track of the information provided by those services without having to keep a bunch of Web pages open or constantly checking them. It notifies you of new events, such as messages or alerts, and provides basic services quickly.
GCalert will access all your Google calendars and display alarms via libnotify for whenever you have alarms set for each event. These alarm widgets do not receive focus (and thus do not take keyboard input away from other applications), yet are clearly visible even on a cluttered desktop.
PySuite is a collection of Python Vim plugins. You need Vim compiled with python to use them. It includes: an outliner similar to TVO; a todo list manager; a project manager (load/unload by directory/project, make an outline of Python files, etc); a calendar that supports adding notes to dates; a plugin to track expenses and balances; a sortable table with fields separated by 2+ spaces; resize (set a list of main Vim window sizes and use two shortcuts to resize -/+); helpgrep (enter a few words and use :helpgrep cmd to search for them in any order); pystripdoc (make a copy of the buffer with stripped out Python docstrings and comments); pyfolddoc (fold Python docstrings and comments); and aligncode (align code by '=' or '#' chars).
Emaigos imports Google contacts and calendars into Emacs. Contacts are stored in a Big Brother Database (BBDB) file, which makes them usable with many Emacs email packages, like Gnus. Google calendars are stored as a single Org-mode file, so events may be viewed as a structured document and possibly shown within an Agenda view. With Emaigos, it's possible to use Google as a contacts and calendars manager, while having all the same data available within Emacs. The original Google contacts and calendars are not modified in any way by Emaigos. The name "Emaigos" is an acronym for "EMAcs Importer for GOogle Stuff".
Synovel Collabsuite provides email, calendaring, and instant messaging solution for enterprises. It consists of a Linux email server with calendar and IM, a Web-based administration panel, a desktop client suite that runs on Windows and Linux, and AJAX-based Web mail access. It uses open standards for communications: IMAP, POP, and SMTP for email, CalDav for calendaring, and Jabber for IM.
Smart PHP Calendar is a Web based, multilingual event calendar. Smart PHP Calendar has four different views. You can define, edit, and delete your events in those views dynamically. Also, you can manage your calendar views, calendars, and calendar styles. Its event search capability lets you find your saved events easily.
Google Calendar Chrome Extension adds a button to your browser toolbar that displays a preview of your calendar while you're navigating. (works on any page). If you're on certain sites where it detects the presence of events, the icon changes to a green "+". Clicking that icon lets you add the event to your Google Calendar, and shows you a Map (if there's a location it could detect.) Supported sites include Facebook, Evite, and any site that uses the hCalendar microformat or derivative microformats such as hResume.