ECW may refer to:
- Extreme Championship Wrestling (formerly Eastern Championship Wrestling), a professional wrestling promotion that operated from 1992 to 2001
- ECW on TNN, a professional wrestling television program produced by the original promotion from 1999 to 2000
- The Alliance (professional wrestling) (originally the WCW/ECW Alliance), a 2001 World Wrestling Federation stable that included Extreme Championship Wrestling
- ECW (WWE), a World Wrestling Entertainment brand and television program from 2006 to 2010 based on the Extreme Championship Wrestling promotion
- Electronic counter-warfare, a set of military measures to counteract enemy radars, missile-guidance, etc.
- English Civil War(s), a series of armed conflicts and political machinations which occurred in England from 1642 to 1651
- Eastern Coach Works, a defunct bus body building company from England
- ECW (file format), an enhanced compressed wavelet file format designed for geospatial imagery
- ECW Press, a Canadian book publisher
ECW (Enhanced Compression Wavelet) is a proprietary wavelet compression image format optimized for aerial and satellite imagery. It was developed by Earth Resource Mapping, and is now owned by Intergraph part of Hexagon AB. The lossy compression format efficiently compresses very large images with fine alternating contrast while retaining their visual quality.
In 1998 ER Mapper Ltd in Perth, Western Australia company founder Stuart Nixon, and two software developers Simon Cope and Mark Sheridan were researching rapid delivery of terabyte sized images over the internet using inexpensive server technology. The outcome of that research was two products, Image Web Server (IWS) and ECW. ECW represented a fundamental mathematical breakthrough enabling Discrete Wavelet Transforms (DWT) and inverse-DWT operations to be performed on very large images very quickly, while only using a tiny amount of RAM. For ECW patents, see and . For IWS patent, see . These patents were assigned to ERDAS (under a former name of Leica Geosystems Geospatial Imaging) July 29, 2007.
After JPEG2000 became an image standard, ER Mapper added tools to read and write JPEG2000 data into the ECW SDK to form the ECW JPEG2000 SDK. After subsequent purchase by ERDAS (themselves subsequently merged into Intergraph), the software development kit was renamed to the ERDAS ECW/JP2 SDK. v5 of the SDK was released on 2 July 2013.
ECW was a professional wrestling television program produced by WWE, based on the independent Extreme Championship Wrestling (ECW) promotion that lasted from 1992 to 2001. The show's name also referred to the ECW brand, in which WWE employees were assigned to work and perform, complementary to WWE's other brands, Raw and SmackDown. It debuted on June 13, 2006, on Sci Fi in the United States and ran for close to four years until it aired its final episode on February 16, 2010, on the rebranded Syfy. It was replaced the following week with WWE NXT.