Particles

Don't think about individual particles, but about the whole effect (or system). You should try to minimize draw calls by grouping the particles together by type to few batches (In ideal case you would have just one VBO or array with all your particles). The best way to do so is offload the particle calculations to the shaders, you can then pass information about size,color etc. as vertex attributes. If you have multiple textures for particles you should create texture atlas and calculate the texture coordinates in your shader.

The fastest way to render particles is using this extension

I do not have a graphics card that supports GLSL, its old :(

that extension looks useful, ill try using that

What kind of culling techniques are there for particles. I would just sort them from to back, and render them in that order. Is that good? Any good articles maybe?