Linux VServer: Cheap and Easy Virtualisation

Matthew Sackman wrote “Whilst projects like Xen and new hardware extensions to CPUs from Intel and AMD allow multiple OSes to run on the same machine at the same time, for me, there are currently few cases where I need this. I work under Linux and all I need is virtualisation to run multiple Linuxes at the same…”

Estimating the number of blog subscriptions

Tom Berger wrote “Unlike traditional website visitors, most readers of a blog use a news aggregator to periodically pull new items from the blog's syndication feed. As a result, the co-relation between the number of requests and the number of times an item is read is broken, and to confuse things even more - many readers use a public aggregator service which saves the feed to a central repository and serves the saved entries to many readers. For such services, growth in the number of subscribers is not represented by an increase in the number of requests made. To get a rough estimate of the number of subscribers to a feed we need to separate between requests made by public services on behalf of more than one user, and requests made by individual news aggregators. If you too are curious about the number of subscribers to your blog (and have access to the HTTP access log of the server hosting it) you can give my little script, Blogalizer, a try.”

Static analysis of Erlang communication

Matthias Radestock wrote “I had a brief email exchange with the developers of [Dialyzer](http://www.it.uu.se/research/group/hipe/dialyzer/), the static analyzer (some might call it a type checker) for [Erlang](http://www.erlang.org/) programs. Currently Dialyzer only performs analysis on the functional fragment of Erlang and I was enquiring whether to extend that to handle communication. That would allow the detection of basic input/output mismatches,…”

Overview of Javascript modes for Emacs

Tony Garnock-Jones wrote “Emacsen.org has a nice roundup of the (apparently only) four javascript-mode implementations for Emacs. I went for number three, Karl Landströmm’s javascript.el, and it’s been working very well.”

S5: A Simple Standards-Based Slide Show System

Lee Coomber wrote “Whilst discussing presentation software the other day with a colleague, he kindly pointed me at S5. It is simple, it is standards-based, and it is a slide show system. In short, it does exactly what is says on the tin: S5 is a slide show format based entirely on XHTML, CSS, and JavaScript. With one…”

Selenium

Lee Coomber wrote “I have been looking for something to help me do some automated functional tests on an existing web application, and came across Selenium. It is a framework that executes tests from within a browser using a combination of Javascript and DHTML. It supports IE, Firefox and Mozilla, thus allowing browser compatibility testing.”

link checker

Matthias Radestock wrote “I was looking around for an easy-to-use, no-fuss command line tool to check the links on a web site. First I tried [wget][]: wget -o wget.log -nv -r -p The resulting `wget.log` contains all the links that were followed. It’s easy to spot the errors but there is no obvious way to get hold of…”

Colour Terminals in (X)Emacs

Matthias Radestock wrote “Some Unix command line tools display text in colour, if you run them in the right kind of terminal, of which the Emacs shell isn’t one. So far this had not really bothered me since in most cases the colours do not convey all that much information. However, recently I was playing with Maude, which…”

Darcszilla – Darcs hooks on patch application

Tony Garnock-Jones wrote “We’ve been using CVSzilla [old link: http://www.cvszilla.org/] here at LShift, and one feature we like that we want in Darcs is the ability for the version-control system to append notes (containing the log message) to a Bugzilla bug record every time a commit is accepted by our central repository. I asked on the darcs-users mailing…”

Java memory profiling with jmap and jhat

Matthias Radestock wrote “My colleagues and I have just spent over a week tracking down a repeated OutOfMemoryError in a fairly complex web application. In the process we looked at the jmap and jhat memory profiling tools for the JVM.”

TiddlyWiki version 2.0

Michael Bridgen wrote “TiddlyWiki is very customisable WikiWiki that lives in a single HTML file. Recently it had a major version release, with some correspondingly major improvements.”

JSON, Squeak, and Seaside

Tony Garnock-Jones wrote “Today I implemented a JSON reader/writer library for Squeak, and a small extension to Seaside‘s existing LivePage features for doing XMLHttpRequest-based server-push. The JSON code is available on Squeakmap and also via SqueakSource, under either SqueakL (see here) or the MIT license. The Seaside extension is still in flux, but I’ll release something as soon…”

Audible Ping

Tony Garnock-Jones wrote “Does your internet go away occasionally? Do you have a computer hooked up to a moderately loud stereo system? Want to know as soon as the link comes back? Here’s a script (put it in a file, e.g. ~/bin/audible-ping) that pings some outside host, playing a short .wav file when ping finally starts to get…”

Sun’s disabling coffee beans

Matthew Sackman wrote “As widely reported (even enthusiastically by people other than Sun themselves), Java 1.5 (otherwise known as Tiger, otherwise known as 5.0) has generics. This is done by erasure originally for reasons of backwards compatibility. The idea was that Sun wanted to be able to compile source code with generics in it and run the generated…”

Searching IMAP in Gnus

Matthias Radestock wrote “I spent a good few hours trying to convince [Gnus](http://www.gnus.org) to search my IMAP folders, under XEmacs. Googling turned up quite a lot of stuff, but most of it is wrong/irrelevant. In the end all I needed to do was: – stick `(require ‘nnir)` in my XEmacs init file – add `(nnir-search-engine imap)` to my…”