Open Source Windows Calendar Software
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Calendar Software for Windows
View 32 business solutionsBrowse free open source Calendar software and projects for Windows below. Use the toggles on the left to filter open source Calendar software by OS, license, language, programming language, and project status.
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Gemini 3 and 200+ AI Models on One PlatformBuild generative AI apps with Vertex AI. Switch between models without switching platforms.
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MongoDB Atlas runs apps anywhereMongoDB Atlas gives you the freedom to build and run modern applications anywhere—across AWS, Azure, and Google Cloud. With global availability in over 115 regions, Atlas lets you deploy close to your users, meet compliance needs, and scale with confidence across any geography.
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Ever wanted to get rid of Outlook ? DavMail is a POP/IMAP/SMTP/Caldav/Carddav/LDAP gateway allowing users to use any mail client with Exchange and Office 365, even from the internet through Outlook Web Access on any platform, tested on MacOSX, Linux and Windows
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Vtiger CRM
An enterprise-class CRM and more!
Vtiger CRM enables sales, support, and marketing teams to organize and collaborate to measurably improve customer experiences and business outcomes. Vtiger CRM also includes email, inventory, project management, and other tools, providing a complete the business management suite. Download Vtiger CRM here or sign up for a free 15-day free trial of the cloud-based application with free updates and support at https://www.vtiger.com/ -
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Outlook CalDav Synchronizer
Sync Outlook with Google, SOGo or any other CalDAV / CardDAV server
Free Outlook Plugin, which synchronizes events, tasks and contacts between Outlook and Google, SOGo, NextCloud, Horde or any other CalDAV or CardDAV server. Supported Outlook versions are 2021, 2019, 2016, 2013, 2010 and 2007 and Office 365 for Desktop. This project was initially developed as a master thesis project at the University of Applied Sciences Technikum Wien, Software Engineering Degree program. Outlook CalDav Synchronizer is Free and Open-Source Software (FOSS), still you can support the project by donating on Sourceforge or directly within the About dialog of our Plugin. Contact us for enterprise support at https://caldavsynchronizer.org/enterprise/contact -
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Group Office groupware and CRM
Take your office and CRM into the cloud!
Installation instructions can be found here: https://groupoffice.readthedocs.io/en/latest/install/install.html Group Office is an open source groupware application. It makes your daily office tasks easier. Share projects, calendars, files and e-mail online. It is a complete solution for all your online office needs. From a customer phone call to a project and finally an invoice. The support system helps to keep your customers happy. Group Office is fast, secure and has privacy by design. You can stay in full control of your data by self hosting your cloud and e-mail. Our document editing solution keeps all data on the secured server instead of synchronising it to all user devices. GroupOffice is open source and modular. Which means it’s easy to customise and extend. You can turn off and on features and it enables any developer to create new modules for the platform. -
Our Free Plans just got better! | Auth0You asked, we delivered! Auth0 is excited to expand our Free and Paid plans to include more options so you can focus on building, deploying, and scaling applications without having to worry about your security. Auth0 now, thank yourself later.
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FullCalendar
Full-sized drag & drop event calendar
FullCalendar generates real React virtual DOM nodes so you can leverage Fiber, React's highly optimized rendering engine. With over 300 settings, and more being added every release, FullCalendar can do just about anything. Reduce your project's bundle size by using FullCalendar's modular plugins. With over 10 years of open source and over 100 contributors, FullCalendar will always have a free and open source core. Level-up by purchasing premium plugins and support. FullCalendar seamlessly integrates with the React JavaScript framework. It provides a component that exactly matches the functionality of FullCalendar’s standard API. This is more than a mere “connector”. It tells the core FullCalendar package to begin rendering with React virtual DOM nodes as opposed to the Preact nodes it normally uses, transforming FullCalendar into a “real” React component. You can learn a bit more from this blog post (more info to come). -
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RedNotebook is a graphical diary and journal helping you to keep track of notes and thoughts. It includes a calendar navigation, customizable templates for each day, export functionality and word clouds. You can also format, tag and search your entries. Please find the latest releases at https://rednotebook.app
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Outlook Google Calendar Sync
Sync your Outlook and Google calendars
Offers calendar synchronization between Outlook and Google, including attendees and reminders. Completely free, no install necessary, works behind web proxies and actively developed. Supports all versions of Outlook from 2003 to 2019/Microsoft365 64-bit! Installable and portable options - even runs from a USB thumbdrive. Synchronises items in any calendar folder, including those shared with you. Differential comparison updates only attributes that have changed. Customizable date range to synchronize, past and future. Frequency of automatic syncs, including push-sync from Outlook. Configurable proxy settings, or use Internet Explorer's. Merge new events into existing on the destination calendar. Prompt on deletion of items. Ability to obfuscate custom words for privacy/security. Option to force items as public or private in target calendar. Syncs recurring items properly as a series. -
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FMA is a SMS Manager, Mobile Phone Monitor, Remote Control Agent, Phonebook Manager, Organizer, Fun and much more; whatever you want it to be, it is whatever a mobile phone should have :-) (Currently based on Sony Ericsson features set).
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Zentyal, Linux Small Business Server
Zentyal is a Linux Small Business Server
Zentyal Server is an easy to use and affordable Linux server, specially designed to meet the needs of small and medium businesses Thanks to Zentyal's Samba integration, Zentyal provides native compatibility with Microsoft Active Directory, allowing you to join Microsoft clients to a domain and manage them easily. Zentyal Server incorporates all the network services required in a small and medium business environment: * Directory & Domain Server with native compatibility with Microsoft Active Directory * Mail Server with ActiveSync and webmail * Gateway with firewall and proxy * Infrastructure Server with DNS/DHCP server, Certification Authority and Virtual Private Networks For more information and download, please access the project's home page. -
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iCalendar Generator
Generate calendars in the iCalendar format
Want to create online calendars so that you can display them on an iPhone's calendar app or in Google Calendar? This can be done by generating calendars in the iCalendar format (RFC 5545), a textual format that can be loaded by different applications. The format of such calendars is defined in RFC 5545, which is not a pleasant reading experience. This package implements RFC 5545 and some extensions from RFC 7986 to provide you an easy-to-use API for creating calendars. It's not our intention to implement these RFC's entirely but to provide a straightforward API that's easy to use. -
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Defalto
Fast, modular open source CRM for growing businesses
Defalto CRM, developed by IT-Solutions4You, is a modern and modular open source CRM system built on over 15 years of real business and CRM development experience. Designed for companies of all sizes, it helps teams manage sales, projects, and customer relationships efficiently through a clean, intuitive interface. The platform combines professional know-how with modern design and functionality. Its free core modules cover essential CRM features, while optional add-ons expand capabilities for advanced business needs. Defalto CRM supports both on-premise and cloud deployment, offering full flexibility and data control. Source code available at: https://github.com/IT-Solutions4You/defalto -
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bootstrap-datepicker
A datepicker for twitter bootstrap
Bootstrap-datepicker provides a flexible datepicker widget in the Bootstrap style. Versions are incremented according to semver. As with bootstrap’s own plugins, datepicker provides a data-api that can be used to instantiate datepickers without the need for custom javascript. You can disable datepicker’s data-api in the same way as you would disable other bootstrap plugins. Most options can be provided via data-attributes. An option can be converted to a data-attribute by taking its name, replacing each uppercase letter with its lowercase equivalent preceded by a dash, and prepending “data-date-” to the result. Methods are called on a datepicker by calling the datepicker function with a string first argument, followed by any arguments the method takes. -
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Project has moved to github: https://github.com/craigk5n/webcalendar WebCalendar is a PHP application used to maintain a calendar for a single user or an intranet group of users. It can also be configured as an event calendar.
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qOrganizer is a general organizer that includes a calendar with schedule,reminders,journal/notes for every day, to-do list.But provides features useful for students such as:timetable and a booklet for marks and absences.It's designed to be easy to use.
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JDavide (per gli amici JD) è un software gratuito per la gestione dello Studio Legale che aiuta l’avvocato nell’espletamento delle operazioni quotidiane. Funzionalità: pratiche, agenda, formulario, atti, parcellazione, rivalutazione, ecc.
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Lifeograph
Advanced personal note taking application
Lifeograph is a diary program to take personal notes on life. It has all essential functionality expected in a diary program and strives to have a clean and streamlined user interface. -
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Date Picker Calendar OpenOffice Calc
Date Picker Calendar extension for OpenOffice Calc
Date Picker Calendar (Latest version 2.60) Set a date in selected cell/cells. Creates a calendar push button in the selected cell and places the date in the cell next to the button. All functions are also in the menu: Tools - Add-Ons. It is possible to change certain settings via the 'Settings' button on the help screen. Calendar Help is located in the help menu of OpenOffice. Toolbar buttons: - Date: the date from the calendar will be inserted in the selected cell/cells. - Date <-Button: a calendar button is created in the selected cell, the date is inserted in the cell to the left of the button. - Button-> Date: a calendar button is created in the selected cell, the date is inserted in the cell to the right of the button. -
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Pendulum
Python datetimes made easy
Pendulum is a Python package to ease datetime's manipulation. It provides classes that are drop-in replacements for the native ones (they inherit from them). Special care has been taken to ensure timezones are handled correctly, and are based on the underlying tzinfo implementation. For example, all comparisons are done in UTC or in the timezone of the datetime being used. There are several different methods available to create a new DateTime instance. datetime() sets the time to 00:00:00 if it's not specified, and the timezone (the tz keyword argument) to UTC. Otherwise it can be a Timezone instance or simply a string timezone value. Pendulum gives access to more attributes and properties than the default datetime class. The __str__ magic method is defined to allow DateTime instances to be printed as a pretty date string when used in a string context. Simple comparison is offered up via the basic operators. -
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Lotus Notes to Google Calendar tool
One-way synchronization from Lotus Notes Calendar to Google Calendar
This is a one-way sync program that will sync your Lotus Notes Calendar to your Google Calendar. No installation is required. Includes many options such as automatic syncing at specified intervals. *Important Privacy Information: https://sourceforge.net/p/lntogoogle/wiki/PrivacyPolicy/ *** Information Update, September 2020: *** Recent issues with Google Synchronization should be fixed with version 1.9.2 which is available for download, now. For typical installation pitfalls, see: https://sourceforge.net/p/lntogoogle/wiki/InstallationPitfalls/ The project was not maintained since its last update in February 2015. However, since I've tracked more than 15.000 Downloads over the last 5 years and still more than 1 million Calendar API-Calls per day, I assume that the tool is still very much in use. So I decided to go back to work. More info: https://sourceforge.net/p/lntogoogle/wiki/Home/ Donations appreciated -
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The VCS to ICS Calendar Converter allows you to convert VCALENDAR files (for example generated by Nokia nbuexplorer or Microsoft Works) to the newer iCalendar format, used by Android and iOS for example. It allows the parsing of events and todo's.
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Amnesia is a reminder that allow to define alarms, stickers (post-its) for reminding you some important stuff, and notes about whatever you want. Alarms can be programmed to appear at a given time, stickers can be placed on desktop to view it anytime.
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IGSuite - Integrated Groupware Suite
IGSuite is a web-ajax-based Integrated Groupware Suite
IGSuite is a web-based Integrated Groupware Suite oriented to be a CRM solution. In the Suite you can find: IGWebMail, IGCalendar, IGContacts, IGArchive, IGWiki, IGTodo, IGChat, Projects, IGFax an HylaFax client, IGFileManager, IGMsg and many other. -
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openCRX - Enterprise Class CRM
professional CRM and groupware service, ready for the cloud
openCRX moved to https://github.com/opencrx -
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BORG is a calendar and task tracking system written in Java. The calendar provides a nice month view, month-print, email reminders, popup reminders and to do list. The task tracker tracks issues through various states.
