what plant is this?

hello, got this plant about 4 years ago and it was just one little plant, about 2cm long. and now its sooooo big.
i moved it into a bigger plot, it just keeps gettin bigger and bigger haha.
well this year its grown upwards, and now looks like its goin to flower.
its never done this befor.
any ways my question is what is this plant?
i think its some kind of cactus?

here are some pics:

 

thanks, now i no what they are

 

It`s a very good specimen John, well done.

 

thanks, i will put some more pics up when the flowers show

 

Fabulous specimen. Well done. They produce a lot of colour, don't they.

 

The rosette the flower came from will die off.

Don't be afraid to break up the cluster, remove the old bits and divide them into new plants - use a compost with plenty of grit