Photoshop remains the industry standard program for web/interface design, for now.
Yes, there are alternatives approaching maturity, but if you are hired to design a website by a client or third party, they will most likely expect the design to be delivered as a PSD.
I've been freelancing at studios across London for the past year and was never once asked if I could use Photoshop — it is assumed.
PS. I'm also working on my own guide to designing websites in Photoshop, which concentrates more on ways to improve and speed up your workflow:
Yes, there are alternatives approaching maturity, but if you are hired to design a website by a client or third party, they will most likely expect the design to be delivered as a PSD.
I've been freelancing at studios across London for the past year and was never once asked if I could use Photoshop — it is assumed.
PS. I'm also working on my own guide to designing websites in Photoshop, which concentrates more on ways to improve and speed up your workflow:
http://greig.cc/photoshop-webdesign/