Naalbinding is a technique whereby sturdy, stretchy fabric may be produced, using an eyed needle and some thread.
There are many different variants of naalbinding - depending on the thickness of the wool, the size of the stitches, the number of stitches picked up by each stitch and on the manner and order in which they are picked up. Some forms resemble modern knitting, others look more like crochet.

This technique was used by the Vikings but is not unique to them - it appears to have been widely used until about the 12th century AD when it began to be superseded by modern knitting as a method of making garments. Naalbound mittens have been found in Iceland, Sweden and Norway. Stockings have been found in Switzerland and socks have been found in Egyptian tombs. As far as I am aware, the only British example is a sock which was found in York (Viking Jorvik) which dates to the 10th century.

Naalbinding is very easy to learn - if you can do blanket stitch then you can do naalbinding. To me, the main drawback is its slowness. It took me nearly as long to make a pair of naalbinding ankle socks as it did to knit a pair of thigh-length stockings (and I wouldn't consider myself as an expert knitter!). Another drawback is that you have to pull the whole thread through (just as in blanket stitch) so you have to use fairly short pieces of wool and you have to keep stopping to join new pieces on.