Bethesda Softworks Plugin File

• Some video games by Bethesda Softworks, including Fallout 3 and The Elder Scrolls III: Oblivion, use the ESP file extension for plugins. These ESP files are associated with ESM files, which contain game data such as textures, video and background music. ESP files contain additional content that overrides the data in the ESM files. An ESP file cannot run in a Bethesda Softworks game without a corresponding ESM file.
  
  

ACD/Labs Analysis File

• An ESP file could also contain data for ACD/Labs software. ACD/Labs programs are designed for chemical corporations to analyze and organize chemistry data. ACD/SpecManager Enterprise organizes databases of chemistry information and includes protections for formulas that a company needs to keep secret.
  
  

Embedded Server Pages

• ESP files may also be embedded server pages -- HTML Web pages with a particular type of embedded JavaScript content. JavaScript is a scripting language that adds interactivity above the plain HTML code used for websites. ESP pages are dynamic Web pages created with appWeb. They usually have the extension ESP, although this depends on how the server configures the file.
  
  

Other File Formats

• Other types of files that use the ESP extension include files for the financial planning software E$Planner, configuration files for the barcode reader software Easy Setup Program, screensaver projects for the open source screensaver program Eclipse, or protected email attachmets by Email Sentinel Pro. A file named UITEXT.ESP is most likely a user interface file for Amiga Personal Paint. In this case, the ESP extension is short for "español" and indicates that the user interface is in Spanish.