backing up your delicious bookmarks

As some may have heard, delicious is being acquired by AVOS. You can transfer your bookmarks, but I decided to make a backup of my bookmarks, just in case.

The quickest way I could think of, was using the RSS feed.

Log into your account on the web and get the URL for the "Private RSS Feed" at the bottom of the page. Change the last part of the URL to be larger than the number of bookmarks you have saved on delicious.

Ex. change
in the URL.

You can safe the page your browser displays when you enter the URL, or you can use wget or another utility to download the feed.

The data is now in your hands and it's up to you to keep it safe.

High resolution dependency graph

I generated a high resolution Gentoo Linux package dependency graph.

Packages are ordered according to their complete Gentoo package name. The result is that the graph shows groupings of packages with lots of dependencies or reverse dependencies. These groupings typically fall under dev-*, kde-*, gnome-*, x11-libs or media-*.

Text labels are only generated for packages with more that 10 dependencies or reverse dependencies. The numbers in brackets after the package name, is the number of dependencies followed by the number of reverse dependencies.

Packages grouped by categories (1600x1600)

A package of particular interest is app-text/sword. It has a total of 165 reverse dependencies!! This is very large number of packages that depends on app-text/sword! All of the packages that depends on app-text/sword seems to be different modules specifically for sword.

A nice picture of (dependency) hell

"Dependency hell" refers the difficulty that arise when installing a software package that requires a lot of other software packages to be installed. The required software packages (or dependencies) may themselves require other software packages to be installed.

To give a better idea of why this can be difficult, I created the following graph.
circle graph of software dependencies
63988 Dependencies between 14319 software packages
This graph shows the dependencies between software packages in the Gentoo Linux operating system. In total there are 14319 packages with 63988 dependencies between them!

Packages are drawn on the circumference of the circle and a dependency is indicated by a line draw from one package to another. The color of a package is randomly generated, while the color of a line is determined by the package that is required by the other packages.

Every package has a line starting on the rim of the circle drawn radially outwards. The length of the line is determined by the amount of other packages that depend on the package.

Here is a closeup of a small part of the graph:
circle graph of software dependenciesThe most common dependencies are development tools. This is a list of the 15 packages with the most reverse dependencies:

Package# of reverse dependencies

The graph was created with data obtained from the Gentoo Portage tree and drawn using the Python Image Libray (PIL).