Finally, after more than a year, magic is in the works! There are currently some limitations to magic, such as you need a staff equipped at the moment to cast these combat spells (spells such as lvl-1 enchant or low level alchemy won't require a staff). Also, the magic tab interface will soon be reworked.
You can buy some basic staves and a wizard hat or robe from the Zaff's Superior Magic Store which is located in the North West building from the centre of Varrock. (I know I need to update the store database images).
You cannot single cast a spell at the moment; you have to click on a spell, providing you have the required amount of runes, and then click on the monster you want to cast that spell on. From then on, all spells casted will be that spell only; however, once I have the new interface working, you will be able to cast a single spell while you have another combat spell set on autocast.
I will next release the rest of the basic combat spells with low and high level alchemy also working!