Subversion UK User Group / Google open source jam writeup

Last Thursday (the 18th) I attended two open source events in London. The first was the third Subversion UK User Group meeting, and the second was Google's second Open Source Jam.

This was almost a disaster for me. I was coming from docklands, and the DLR was suspended due to the storms that hit Europe. What should have been a 20 minute journey to Bank station turned in to a 50 minute nightmare. I was due to give the first presentation, and had visions of causing problems for everyone else. And visions of fainting. Mental note -- next time do not give blood 2 hours before delivering a talk. Or perhaps, better not to deliver a presentation 2 hours after giving blood.

Anyway, I just made it in time. The transport disruption caused by the weather meant that there weren't as many people as the last get together (about 12 I think) but this also meant that it was also possible to have more inclusive discussions about points raised by the presentations.

I think mine went well. There's a PDF, slide-only version of "Subversion and Perl, a tour through CPAN". It ended up a tiny bit rushed -- 24 slides in 25 minutes. I should probably allow 90 seconds per slide for those sorts of slides next time. It's a difficult balance to strike when writing them. It's all very well using the Takahashi Method (big text, very few words, clkao did that to great effect at the previous meeting), but they're not necessarily going to be very useful to the audience afterwards without extensive notes.

Duane Griffin commented to me that the information about SVN::Notify had saved him some work, so I know at least one person found it useful :-)

The next presentation was from C. Michael Pilato, going through some of what's up-and-coming in Subversion over the next few minor releases (and 2.0). No real surprises for me there, since I follow the dev mailing list. I was disappointed to discover that this was a conference call. When I saw his name on the schedule I thought CollabNet might have flown him over to do some customer consulting. I was looking forward to shaking his hand and saying "Thanks for the commit bit".

Andrew Heald followed this with a "lessons learned" discussion / presentation about his experiences migrating a relatively large group of developers (around 80 or so) from CVS to Subversion for Catlin. I hope the slides will be online soon.

The last presentation and demonstration was from Guido Haarmans, talking about the recently introduced Open CollabNet.

I've had a poke around Open CollabNet previously, and I confess that I'm not quite getting "it". This might well be because it's not aimed at me. There's a fair amount of content on there, and it includes a number of web based forums. But I find that that just makes things harder to find -- if you're looking for Subversion info do you go to Open CollabNet or And what do the web forums do that the users and dev mailing lists don't?

And it doesn't help that there are no updated feeds of the content available. So it becomes yet another website that I have to remember to visit on a periodic basis (and I can't roll it up in to Planet Subversion).

On the flip-side, at work the next day I needed a site to point someone completely new to Subversion at, and they found Open CollabNet quite helpful. So, as I say, I could very well just not be in the target audience.

And then it was on to the Google Open Source Jam.

I travelled down with Duane Griffin and Dave Hodgkinson, who'd also been at the Subversion meeting. During the journey Duane and I chatted about tools for extracting statistics from Subversion repositories.

The Google event was organised in to two main sections. First, once we'd arrived, chatted a little bit, anyone that wanted to had the opportunity to give a lightning talk (5 or so minutes) about anything interesting that they were working on. A few things caught my eye -- mostly in the "That looks interesting" category, rather than the "I'll be able to make a positive contribution to that project" category. But I've got plenty of open source stuff on my plate at the moment, so that's no bad thing.

Simon Stewart introduced WebDriver, a tool to make it easy for developers to carry automated tests of webapps, even if they use Ajax and similar technologies. Since it's hosted at Google I was able show Simon the SVN::Web front end to the WebDriver repo, which he seemed impressed by.

Stathis Sideris showed us ditaa. This is very geeky -- it takes ASCII art diagrams like this:

    +--------+   +-------+    +-------+
| | --+ ditaa +--> | |
| Text | +-------+ |diagram|
|Document| |!magic!| | |
| {d}| | | | |
+---+----+ +-------+ +-------+
: ^
| Lots of work |

and converts them to something like this;

ditaa converted image

The other presentation that caught my eye was from Benoit Xhenseval, talking about, amongst other things, StatSVN. This is a Java application that gathers and reports on statistics about Subversion repositories.

As I mentioned earlier, I'd been talking about this sort of thing with Duane on the way over, and it's this sort of serendipitous meeting that events like this help facilitate.

We talked about it some more. After a bit of digging in to how it works I suggested they consider splitting the code in to two parts -- a back end that is responsible for gathering and storing the data, and a front end that can query the data and generate reports (web based, e-mail, and so on). That would make it possible to integrate it with a number of other tools. Obviously, my interest is in bringing something like this SVN::Web.

Some other Perl mongers were in attendance and I took the opportunity to catch up with some of them. Nick Clark detailed some issues he was having with P4 data export that make migration to Subversion difficult for Perl -- if I understand correctly it's about not being able to get at the P4 metadata that details which changesets have been integrated (which revisions have been merged, in Subversion parlance).

I was also able to jump in part way through an overheard conversation about scraping websites and sending to WAP devices. I gave an impromptu intro to Plagger and the wealth of ways it might be able to help with this.

Next time I should remember to take a camera. Stuart Yeates was snapping away, and has a set of photos from the Google Open Source Jam event on Flickr.

Thanks to the organisers, in particular Joe Walnes -- providing space, projects, wireless, food, and drinks works well. Maybe not conducive to actually getting patches committed there and then (perhaps that's just me), due to eclectic nature of projects. But it's a great communication enabler.

1 comment:

  1. Hi Nik,

    Thanks for your feedback on openCollabNet. The site is young and we are certainly looking at many improvements based on feedback we receive (release early, release often). Amongst them are RSS, more Subversion related content and a better organization of the site. I’ll let you know when we have improvements in beta so you can give us feedback.

    As you mentioned, there is already a lot of good stuff on the site, from discussion forums to technical articles and webcast to downloadable software. We have downloads for CollabNet Subversion (open source Subversion compiled, tested and certified by CollabNet) and you can download a free fifteen user version of CollabNet Enterprise Edition, our collaboration platform for distributed teams. There are also some Subversion related tools and more downloadable software and extensions will follow.

    You asked about the difference with As you know, CollabNet initiated the Subversion project, we have a team of committers and have a long track record of Subversion support. We want to bring this experience to web so Subversion and CollabNet users can benefit from it. Now, although CollabNet hosts, the pages belong to the open source Subversion community. So we created our own “outlet” to reach out to the Subversion and CollabNet community: openCollabNet. As we grow this site, it will become more and more useful to you.

    Thanks again for your feedback, we will continuously make openCollabNet better and feedback really helps, please keep it coming: what content would you like to see, what features, what downloads etc.? My email address is

    Guido Haarmans
    Developer Relations