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.

Here are some pre-release DAViCal 0.9.5.90 (i.e. nearly 0.9.6) packages now. Since there is a lot of refactoring that has gone on under the covers here, I'll publish these packages so that people can tell me about all my embarassing mistakes, and I can correct them, before I upload them to places where they might get installed more or less automatically.

In particular if you do find problems with these, and can catch me on the #davical on irc.oftc.net during the coming week I should be able to include a fix into the real 0.9.6 release next week. If you can't get on IRC then an e-mail will also be fine.

The full release notes are here but the short version is that this fixes a number of bugs, notably one to do with importing calendars containing repeating events with exceptions. The big change is that this adds the initial support for the draft scheduling extensions to CalDAV, in particular the lookup of free/busy information.

Updated

In true pre-release fashion I forgot to actually enable the scheduling extensions stuff, so I've put new packages (0.9.5.91) on there now with that enabled... :-)

Writing free, open-source software is an incredibly public activity. Everything you do is in the public eye, and google will inevitably discover your site, and then other people will find your software, and download it, and this is a good thing. It's why you're doing it, after all, and it's so nice to receive those occasional 'Thank you for your software' e-mails. There are occasional exceptions, however.

Today's practical exercise is to demonstrate your skills responding to the annual student exercise question, like this one, following on to finish a real exchange while still retaining your sanity to the maximum extent possible. Humour will receive bonus points.

Here goes. First up, we have an e-mail arriving out of the blue which looks like this:

how to run the caldav server
in window
i have download it from the http://wiki.davical.org/

Finally, I have released DAViCal 0.9.5. Hopefully this will resolve the series of installation- and upgrade- related problems which plagued the 0.9.4 release.

Thanks for everyone being patient while this release was thoroughly tested through five pre-release versions, and especially thanks to those patient people who helped test those pre-releases.

Now if I don't get too distracted by:

• processing my GPS tracks of the last two weeks around the South Island
• Uploading my last six months worth of photos
• Making sure the kids have done their homework
• Describing the places near where I live.
• ...anything else that catches my interest

... then maybe I will be able to really concentrate on nailing the scheduling extensions work over the next couple of months...

Wish me luck!

Quite a few people seem impressed with the new release of Leopard, and are now looking for a CalDAV server to use with their shiny new iCal app. Unfortunately it seems that Apple wrote this primarily to work with their own (free, open-source) calendar server, which has the side effect that it doesn't work with DAViCal.

Part of the "doesn't work" is due to DAViCal not implementing some areas of the CalDAV specification, which is fair enough. Part of it is due to DAViCal not implementing some draft extensions to the CalDAV specification, which I can also understand, since it allows them to provide some useful features that those extensions are designed to support. There also seem to be some parts of the "doesn't work" which are due to a dependence on extensions beyond either of these cases, which is a little more disappointing - and quite a bit harder to implement.

So far I have made some fixes to the first point, and some additions towards parts of the second, but as of today it still does not work. This is complicated by my not having access to a Mac. Things are looking up, however, because Tom Robinson has kindly agreed to loan me a Mac running Leopard from next week.

In order to "clear the slate" for that, I will be releasing a 0.9.2 over the weekend with the various minor enhancements and fixes that have been applied over the last week. So although this upcoming release will let you add your DAViCal account to iCal 3, it still won't actually work with it. I'm hoping that ready access to the application will enable me to correct that fairly quickly.

Also waiting in the wings (and which unfortunately won't be in 0.9.2 either) Maxime Delorme has been working on SyncML support, and is nearly ready with a patch, so we can look forward to that addition fairly soon also.