In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Looks like an old rug or a computer chip.
Source Patutin Sergey
Sharp pixel pattern, just like the good old days.
Source Paridhi
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The original has been presented as black on transparent and stored in the pattern definitions. To retrieve the unit tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen
Black brick wall pattern. Brick your site up!
Source Alex Parker