Now that Adobe has made Photoshop CC the linchpin of its Creative Cloud subscription strategy, photo enthusiasts are more than ever seeking alternatives to the engine that has driven the modern image-editing industry for more than 20 years.Subscriptions to Photoshop via Creative Cloud cost $50 per month and are popular with a certain segment of Adobe users, mostly the cadre of commercial artists, graphic designers, Web developers, and photographers who use multiple apps for high-end professional work.To sweeten the deal for photographers, Adobe is now offering