You can use the following logs for your site or whatever you want inside your project using Vortex Library.
A really big Vortex logo in PNG
A Vortex logo in PNG format (size 200x200)
A Vortex log in PNG format (size 100x100)
A wide logo suitable for a web site in PNG format (size 349x100)
Did Vortex catch you? A vortex logo in PNG format (size 420x100)
A powered-by image (size 361x100)