In order to sync calendars and contacts between all of your devices, or to share calendars and contacts with others, you must sync BusyCal and BusyContacts with a server. BusyCal and BusyContacts are compatible with CalDAV, CardDAV and Exchange servers.

You can host your own in-house server (OS X Server, Exchange, Kerio, Zimbra, etc.) or use one of the free or low-cost cloud services available (iCloud, Google, Fastmail, Fruux(not recommended), Kerio, Office 365, etc.). This article examines the pros and cons of syncing BusyCal and BusyContacts with each of these cloud services.

Each cloud service has its strengths and weaknesses and is best suited to a certain demographic. Some services are designed for consumers while others are targeted at small businesses or the enterprise. When choosing a cloud service there are many factors to consider including cost, device support, features, calendar and contact sharing, group scheduling, and custom domain support.

You are not limited to one service. You can sync BusyCal and BusyContacts with multiple services simultaneously. However, for best results when performing sharing or group scheduling, you should standardize on one cloud service for your entire workgroup.

Below is a matrix depicting the key features supported by each cloud service, followed by a summary of the pros and cons of each.

Cloud service comparison

	iCloud	Google	Fruux	Kerio	Exchange
Syncs w/BusyCal & BusyContacts	✔︎	✔︎	✔︎	✔︎	✔︎
Syncs w/Mac OS X	✔︎	✔︎	✔︎	✔︎	✔︎
Syncs w/iOS	✔︎	✔︎	✔︎	✔︎	✔︎
Syncs w/Android	✔︎	✔︎	✔︎	✔︎	✔︎
Syncs w/Windows	✔︎	✔︎	✔︎	✔︎	✔︎
To Dos	✔︎	-	✔︎	✔︎	✔︎
Contact Sharing	-	-	✔︎	✔︎	✔︎
Calendar Sharing	✔︎	✔︎	✔︎	✔︎	✔︎
Calendar Publishing	ics	ics/web	ics/web	ics	ics
Group Scheduling (free/busy)	-	✔︎	✔︎	✔︎	✔︎
Custom Domains	-	✔︎	✔︎	✔︎	✔︎

Glossary

• Syncs w/BusyCal & BusyContacts — Server syncs with BusyCal and BusyContacts.
• Syncs w/Mac OS X — Server syncs with the built-in Calendar and Contacts apps on OS X.
• Syncs w/iOS — Server syncs with the built-in Calendar and Contacts apps on iOS.
• Syncs w/Android — Server syncs with the built-in Calendar and Address Book apps on Android. May require a third-party plugin.
• Syncs w/Windows — Server syncs with Outlook on Windows. May require a third-party plugin.
• To Dos — Server syncs To Dos with BusyCal (and the Reminders app on OS X and iOS).
• Contact Sharing — Server supports contact sharing.
• Calendar Sharing — Server supports calendar sharing.
• Calendar Publishing — Server supports publishing a read-only calendar that others can subscribe to as an ics feed, or view in a web browser.
• Group Scheduling — Server supports group scheduling (e.g. free/busy viewing).
• Custom Domains — Server supports custom domains, so that meeting invitations are delivered from your business email address.

iCloud

iCloud is a free service offered by Apple that syncs with BusyCal and BusyContacts via CalDAV and CardDAV. iCloud syncs natively with Mac and iOS devices, and plugins are available for syncing with Android and Windows Outlook.

iCloud supports calendar sharing, enabling you to share calendars with other iCloud users with read/write access. You can also publish your calendars in read-only ics format for others to subscribe to.

iCloud calendar sharing is ideal for families and very small workgroups but is not suitable for businesses. There are no admin controls for creating users, groups and shared calendars, so users must individually share their calendars in a peer-to-peer fashion. There are no group scheduling features for viewing free/busy time and scheduling resources like conference rooms and projectors. There are limits to the number of calendars and events you can store on iCloud, which can easily be exceeded in a business environment. And there is no support for custom domains, which means any meeting requests you send will be sent from your personal icloud email address.

Lastly, iCloud does not support contact sharing.

Pros:

• Free
• Native support for OS X and iOS
• Suitable for individual and family use

Cons:

• Plugins are required for syncing with Android and Windows Outlook
• Does not support contact sharing with BusyContacts
• Not suitable for businesses

Google

Google Calendar and Contacts are free services offered by Google that sync with BusyCal and BusyContacts via CalDAV and CardDAV. Google syncs natively with Mac, iOS, and Android devices, and plugins are available for syncing with Windows Outlook. Individuals can use Google Calendar and Contacts for free, and a paid Google Apps account is available for businesses.

Google Calendar supports calendar sharing, enabling you to share calendars with other Google Calendar users with read/write access. You can also publish read-only calendars for others to view in a web browser, or subscribe to in ics format.

If you are a Google Apps customer, admin controls are provided for configuring users and groups, and sharing calendars with members of your organization. You can also view free/busy availability of other users in your workgroup when scheduling meetings. And Google Apps supports custom domains, so you can send meeting requests from your business email address.

Google would prefer that you use your web browswer for interacting with its services and does not provide access to all of its features to third-party apps. For example, some features like creating new calendars or sharing calendars can only be configured through the web interface. Further, Google's CalDAV implementation does not support all of BusyCal's features (To Dos, attachments, graphics, etc.).

Lastly, Google does not support contact sharing.

Pros:

• Free for individuals; low-cost for Google Apps customers
• Native support for OS X, iOS and Android
• Google Apps provides business-oriented features, such as admin controls, group scheduling and custom domains

Cons:

• CalDAV and CardDAV sync support is limited; Some features only accessible in web-browser
• Plugin required for syncing with Windows Outlook
• Does not support contact sharing with BusyContacts
• Does not support To Do syncing with BusyCal

Fruux

UPDATE: As of July 2020, Fruux servers have introduced a bug where it would either return malformed responses to requests or would fail to process requests of a certain size. This bug has not been fixed (last checked Jan 2022) and affects everyone. Fruux customer care has not responded to complaints. Unfortunately we would not recommend using Fruux. Instead please explore many of the other popular services out there: iCloud / Google / Fastmail and so on.

Fruux is a free or low-cost cloud service targeted at teams and small businesses that wish to share calendars, tasks and contacts. Fruux syncs with BusyCal and BusyContacts via CalDAV and CardDAV. It syncs natively with Mac and iOS devices, and plugins are available for syncing with Android and Windows Outlook.

Fruux supports calendar sharing, enabling you to share calendars with other Fruux users with read/write access. You can also publish read-only calendars for others to view in a web browser, or subscribe to in ics format.

Fruux provides admin controls for configuring users and groups, and for sharing calendars and contacts with other team members. You can also view free/busy availability of other users in your workgroup when scheduling meetings. And Fruux sends meeting requests from your existing email address.

Fruux supports contact sharing and multiple address books. In fact, it is the only CardDAV service that provides seamless integration with BusyContacts for sharing address books.

Fruux is a reliable sync service that works beautifully with BusyCal and BusyContacts. We think it's a great option for teams and small businesses that want to share calendars and contacts.

Pros:

• Free for individuals; low-cost for teams
• Native support for OS X and iOS
• Supports contact sharing with BusyContacts
• Provides business-oriented features, such as admin controls, group scheduling and custom domains

Cons:

• Plugins required for syncing with Android and Windows Outlook
• No email service provided (which may be considered a benefit, as you can continue using your existing email address/service)
• Based in Europe and billing is in Euros for US customers

Kerio

Kerio is an alternative to Exchange targeted at small to medium sized businesses. You can run your own in-house Kerio server, or select a vendor that provides Kerio hosting like GetSync'd Hosted Kerio and others. Kerio can sync with BusyCal and BusyContacts via CalDAV/CardDAV or Exchange (EWS) protocol. It syncs natively with Mac and iOS devices, and plugins are available for syncing with Android and Windows Outlook.

Kerio supports calendar sharing, enabling you to share calendars with other Kerio users with read/write access. You can also publish your calendars in read-only ics format for others to subscribe to.

Kerio provides admin controls for configuring users and groups, and for sharing calendars and contacts with other team members. You can also view free/busy availability of other users in your workgroup when scheduling meetings. And Kerio supports custom domains, so you can send meeting requests from your business email address.

Kerio supports contact sharing and multiple address books. You must create and configure shared address books with the Kerio web client, but once you've done that the shared address books will appear in BusyContacts.

Lastly, Kerio supports sharing of calendars and contacts across platforms so Mac users running BusyCal or BusyContacts can share with Windows users running Outlook.

Pros:

• Alternative to Exchange for small to medium sized businesses
• Native support for OS X and iOS
• Supports contact sharing with BusyContacts
• Provides business-oriented features, such as admin controls, group scheduling and custom domains

Cons:

• Not free
• Plugins required for syncing with Android and Windows Outlook
• May require IT support for configuration

Exchange

Exchange has long been the gold standard for large organizations, particularly those that run Windows. But it's not just for Windows anymore. Native support for Exchange is built-in to all platforms (Mac, iOS, Android and Windows). BusyCal and BusyContacts support Exchange, allowing you to seamlessly sync calendars and contacts on your Mac with Windows Outlook through Exchange.

Most large organizations with dedicated IT staff run their own Exchange servers in-house. But that's not a requirement. There are many service providers offering affordably priced Exchange hosting for small, medium and large businesses, including Office 365, Rackspace, and GoDaddy.

Exchange supports calendar sharing, enabling you to share calendars with other Exchange users with read/write access. You can also publish your calendars in read-only ics format for others to subscribe to.

Exchange provides admin controls for configuring users, groups, and resources, and for sharing calendars and contacts with other team members. You can also view free/busy availability of other users in your workgroup when scheduling meetings. And Exchange supports custom domains, so you can send meeting requests from your business email address.

Exchange supports contact sharing and multiple address books in BusyContacts. You can create multiple address books in BusyContacts and share them with other users, incuding those running Windows Outlook.

If you need to sync and share calendars and contacts with Windows Outlook users, Exchange is a good choice.

Pros:

• Ideal for large organizations, particularly those running Windows Outlook
• Native support for all platforms (Mac, iOS, Android and Windows)
• Supports contact sharing with BusyContacts
• Provides business-oriented features, such as admin controls, group scheduling and custom domains

Cons:

• Not free
• May require IT support for configuration

Summary

There are many cloud syncing services to choose from. Choose the service that is right for you based on the devices you use, and whether you need to share calendars and contacts, or schedule meetings. And remember, you are not limited to just one service. You can sync with multiple services simultaneously (e.g. sync work related calendars with Exchange and personal calendars with iCloud).

iCloud is a good choice if you are purely using Mac and iOS, and only need to share calendars with family members. iCloud does not support contact sharing, group scheduling or custom domains.

Google is a good choice if you are a Google Apps user and want to share calendars and schedule meetings with members of your workgroup, and use a custom domain. It also works well with Android devices. However, some features can only be accessed through a web browser and it does not support syncing of To Dos with BusyCal or contact sharing with BusyContacts.

Fruux is a good choice for small businesses that want to share calendars and contacts, schedule meetings, and use a custom domain. It is the best choice for contact sharing with BusyContacts. UPDATE 2022: We no longer recommend Fruux as the server introduced bugs some time ago that have not been fixed. We recommend Fastmail instead.

Kerio is a good choice for small or medium sized businesses looking for an alternative to Exchange. It supports calendar and contact sharing, groups scheduling, and custom domains.

Exchange is a good choice for medium or large businesses that need cross-platform compatibility with Windows Outlook. It supports calendar and contact sharing, groups scheduling, and custom domains.

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