In digital photography, the digital post-processing replaces the need of chemicals and darkroom with ever more complex softwares, such as Photoshop version CS-5. As a result, the verb "photoshop" is synonymous to the term post-processing.
One of the other most widely used software is Adobe Lightroom. The following article is a comprehensive review of the latest version, the Lightroom 4:
http://www.dpreview.com/articles/748116 ... m-4-reviewGood birding and photography.