Back in 2005 I saw that a new open standard was being developed for calendaring, and I thought it would be a great idea to implement it. Nothing too complicated - just a really simple implementation...

And thus was born the "Really Simple CalDAV Store".

A few years later, when I got about 90% of the way through implementing the base CalDAV specification, I realised that "Really Simple" and "Calendar" don't actually happen in the universe we inhabit, so after much deliberation the project got renamed to "DAViCal".

Now, in 2012, DAViCal is one of the leading CalDAV servers available, and I spend quite a lot of my time helping people who want to use it. Earlier in the year I was looking at the web server logs and noticed that in a four week period (i.e. as far as my logs go back) there had been several thousand unique sources of hits on the URL that DAViCal uses internally to find out what the latest version is when you browse to the '/setup.php' page.

This got me wondering how many DAViCal installations there are out there, and how big they might be, and so forth but since DAViCal is free open source software, there isn't a simple way to answer those questions.

I thought that it must be time to run a survey of DAViCal users everywhere to try and find out what the scale of the penetration is. How big (and how small) are the installations running DAViCal? What... Well: lets save the questions for the actual place where you can put answers :-)

So click here and take the survey right now... you know you want to :-)

The German Linux Magazine runs a sponsored an "Open Source Lounge" at CeBIT each year. Last year I put in a proposal for DAViCal and it got accepted! With some airfare support from InternetNZ I got to showcase my Free Software project at the largest IT trade fair in the world.

If you have an open source project to promote I can't recommend this highly enough. Below is a review of my experience at CeBIT early this year. This is long overdue for posting, and I'm prompted now because submissions are now open for the Open Source Project Lounge at CeBIT in 2012. Apply now.

DAViCal 0.9.9.4 is now available, along with AWL 0.46.

This is a recommended upgrade with a focus on stability and reliability.

Release notes are on the wiki at http://wiki.davical.org/w/Release_Notes/0.9.9.4.

Most of the changes are subtle: fixes to small bugs or adjustments to correctness in respect to standards. In particular there were some errors in handling of various requests for addressbook data, and the support for WebDAV synchronisation is updated to draft -04 of the specification.

One notable addition is the new '/feed.php/username/calendar/' URL which will provide an Atom feed of the events added to a calendar. This is pretty experimental at present, but any problems with it won't affect the rest of DAViCal so I felt it safe to include in a stable release series.

I've also created a DAViCal Announce mailing list which in the future will be the primary place that notifications like this are sent to, so those of you who are subscribed here but really only want to see announcements should subscribe to that list.

In a few weeks time (well, when I remember, I guess :-) I want to move the DAViCal General mailing list to a lists.davical.org mailing list. As of today I've moved the DAViCal developers mailing list there already (pretty easy since it did not involve moving servers) but the old address for that one will continue to work indefinitely.

Also, as of yesterday, the sourceforge.net project name for DAViCal finally got changed, so DAViCal is now at http://sourceforge.net/projects/davical - yay!

At the end of January I will be presenting about Calendaring and Free Software at Linux.Conf.AU 2011 in Brisbane - I hope you've all got your tickets already, because there isn't much time left now :-)

Finally, six months after releasing 0.9.9, and about three months after when I would have preferred to have released it, I've released version 0.9.9.2 of DAViCal. In fact most of the changes were included in 0.9.9.1 which was more quietly released last week to a select audience of keen testers. They found a few bugs, and these are resolved and so 0.9.9.2 is the release I hope people will be able to find useful for some time into the future.

In a couple of weeks, once it's been in Debian Sid for a respectable time, I hope to ask for a freeze exception so that we can include this version into Debian Squeeze when it is released. Given that I missed the cut by a hair or two for Lenny so there is no DAViCal currently in a Debian release I think I can be hopeful on this count. Certainly this fixes a few issues with 0.9.9 which will cause annoyance if they haunt me for the next few years :-)

As well as the rafts of bug fixes and such, the exciting new feature added in 0.9.9.2 is the first support for CardDAV. At this point you need to create the addressbook collection yourself, and there is no import facility, but at least you might be able to use DAViCal to store your contacts.

Enjoy!

I've been working on implementing CardDAV support into DAViCal at the moment, and the first problem I encountered when I went to try and use it from iCal, was that the configuration on iCal didn't seem to want to let me enter a URL to my addressbook.

I've now released DAViCal 0.9.9, after five pretty intensive weeks of work. This includes a number of features that were implemented to support dotCal, which has now replaced their old Cosmo backend with DAViCal to break through a performance bottleneck. That turned into a six-week challenge, because Cosmo had wandered some distance from where calendaring standards are currently going, and so there was a lot of work under the covers of dotCal to switch from using various Cosmo-specific features to do the same thing, using open calendaring standards like CalDAV.

After a whole bunch of drastic changes, lots of bugfixes, rewriting and refactoring, I released DAViCal 0.9.8 on Christmas day last year. I didn't release it very publicly, because I knew it sucked significantly. In an increasingly fast turnaround I've subsequently released 0.9.8.1 to a somewhat wider audience while I was at the recent Calendaring and Scheduling Consortium meeting in Costa Mesa at the beginning of the month. Earlier this week I released 0.9.8.2 to the more interested of the DAViCal userbase. So finally, yesterday, I released DAViCal 0.9.8.3 to fix the few significant problems that were left with that, and this is the release that I'm telling everyone about, because I believe it should be a good stable platform to people who want to upgrade their production DAViCal servers, or who have been hanging back from using DAViCal until the platform was a little more stable.

I spent last week at the CalConnect XVI meeting of the Calendaring and Scheduling Consortium hosted by Apple Computer in Cupertino. I'd been hoping to get 0.9.7.3 released before I got there so I could concentrate on some of the more aggressive enhancement plans while I was there, but in the end I didn't manage to release until the Tuesday, during the event. Then, after some interaction with Kerio and a small but important bug that was found, I decided to release 0.9.7.4 with a very few small changes before moving onto the more radical enhancement plans I continue to work through at present towards a 0.9.8 release in a few weeks.

The release notes for both releases are on the wiki, including details of downloading and so forth:

• http://wiki.davical.org/w/Release_Notes/0.9.7.3
• http://wiki.davical.org/w/Release_Notes/0.9.7.4

At CalConnect itself, the first half of the week was an interoperability meeting which I was an observer at, though I did set up a server for people to test against, and the folk from Apple, Sun and Kerio were kind enough to test against this, including a very early version of the Symbian CalDAV client which is likely to be released sometime next year.

The second half of the week was a much more participative process, and gave me a much greater understanding of the general flow of the standards which are forming in the future. In particular it was interesting to get an idea of how close (or far away) the various nascent standards under development are. Some of the closest ones seem to be the Scheduling Extensions which is at draft 8, and will probably have only one or two more clarifying drafts before becoming an RFC. Next closest is probably the proposed CardDAV standard, and implementation of both of these in DAViCal is a priority for me.

The first thing I discovered too, was RFC5689, which is now implemented in HEAD and will be in 0.9.8. Another worthwhile standard, and relatively simple, is the Draft WebDAV Sync which is used by iCal4 if available, and which I have also implemented since leaving Cupertino. I expect there will still be some changes to the webdav sync specification, but it's relatively encapsulated so the effect of any changes are not going to be sweeping.

Support for the Scheduling Extensions for CalDAV, which I am working on now, will be more complete in 0.9.8, though probably still with a few missing parts. It is a large specification though it looks to be pretty stable now and is definitely time to move forward with it.

What the trip to Cupertino definitely showed me is that there is still a place for DAViCal in the available set of CalDAV servers. While there are starting to be quite a few around, and many are maturing nicely, there is still a niche for a free, standalone, SQL-based implementation like DAViCal and it is only through having a vibrant community of implementors around calendaring that we can flesh out the usable and useful standards that are continuing to come out of CalConnect.

Ultimately what impressed me the most were the people around CalConnect, who stand out as being a bunch of dedicated and thoughtful folk who really understand the importance of interoperation and open standards in this area. I do hope I have the good fortune to make it to another event at some point in the future.

I released a new 0.9.7.2 version of DAViCal yesterday. This reflects quite a lot of stability and small fixes for some subtle problems, and quite a lot of work with the iPhone, adding the possibility of a simpler configuration experience for iPhone users.

For several years I've wanted to join the Calendaring and Scheduling Consortium and go to one of their events to get a chance to meet face-to-face with some of the luminaries in the calendaring world, but every time there is an event it seems to conflict with either linux.conf.au or my brother's wedding or something. Finally I've decided I can make the next meeting, so I've paid over the money to join the organisation and I'm travelling to the US next month for 'CalConnect XVI'. With that on my mind when I saw an HP 110 mini netbook on sale for NZD$588 from Harvey Normans I finally flipped over the 'shall I get one' threshold, hoping it will make a good 'travel laptop' for the upcoming trip.

Several weeks ago I was browsing around CalConnect wondering, as you do, if the timing will ever be right and the backing available for me to visit one of their meetings. It seems that the planets may actually finally be in alignment and I am really hoping that I can get to CalConnect XVI from 5th to 9th of October - though I will have to save my pennies.

In passing I noticed that the FREEBUSY Technical Committee has just published a Proposal for Freebusy Read URL, defining a bunch of optional parameters that can be used in queries against a freebusy URL. As calendar servers increase in power and scope it seems natural that these things will become more useful even if you might have thought time had passed them by, replacing them with more advanced CalDAV scheduling extensions.

Since DAViCal has always had Freebusy URLs, and in fact accepted a couple of simple parameters in them already it turned out to be a simple matter to provide these standardised ones as well. This change was included in DAViCal 0.9.7 which I released quietly into the wild a few days ago.

After far too long (too many holidays away from my keyboard :-) I've released DAViCal 0.9.6.3 and AWL 0.36. This is mostly a stability release, fixing all those little niggles that might only affect a few corner cases, but it frees me up now to concentrate on adding more functionality for a 0.9.7 release in due course. Hopefully this will be the last in the 0.9.6.x series.

More information in the DAViCal release notes on the wiki.

There are quite a few changes to the AWL libraries which this release depends on, but most of those changes have been driven by my Work Request Management System and Capital APMS projects, rather than from DAViCal.

Tomorrow will be a challenging day, herding the kids through the airports to get to Hobart for a holiday in Tasmania before linux.conf.au 2009 in a couple more weeks.

Sadly I didn't get the DAViCal release out over Christmas that I'd hoped for, and realistically I should face up to the fact that I won't have much chance to push it out until I get back...

Still, it might happen, so don't lose hope! And if you're desperate the current Git head is pretty safe too - so long as you use the head for AWL as well.

I'll only have sporadic net access (until LCA anyway), and my cellphone won't reach me at all, so I guess the world will have to get along without me for a few weeks :-)

Have a Happy New Year - we won't be partying tonight, with a 4:00am start in the morning!

Today someone asked me to take a look at an Evolution enhancement that's just begging to get into trunk. Since this is a Gnome program in a subversion repository I've commenced the process of cloning the repository so I can look at the issue against the current head.

At the current rate I should have a copy of the repository by early tomorrow morning, in order to be able to start looking at it. Of course today is when I actually do have some time to spare, and I hope to be fast asleep at the time when I expect this to finish.

Presumably subversion isn't this slow for everyone, but since my latency to their repository is 300mS I'm probably on the worst end the pain, with each commit seemingly taking around a second. It sure would be nice if subversion provided some kind of chunked compression of these five-year-old commits, so I could be bandwidth limited, rather than latency challenged.

The addition of a day to the checkout of a software project must be a significant barrier to entry for anyone considering contributing. It makes it much less likely to be opportunistic.

So far I'm up to r3600 in 75 minutes. That's 75 minutes that I could have spent actually looking at the code, but now it's time for me to go and vote for me...

Well, it seems that there were few problems with the pre-release of DAViCal I pushed out last week, so 0.9.6 is out now.

The full release notes are on the wiki. The biggest change is that this release now supports free/busy using the method defined in the draft scheduling extensions for CalDAV, so it's possible to schedule meetings with Sunbird/Lightning or iCal, and possibly other clients if they support that.

Now I can concentrate on getting some paid work done for a few weeks before I start on the next stage.

Updated

After release I discovered that due to the changed behaviour of DAViCal, interoperation with Mozilla Sunbird/Lightning 0.8 was no longer working. A new 0.9.6.1 version has been released to resolve this issue.