1. 1 Browser Compatibility Assessment TAC Presentation May 28, 2015 David Forfia Director, Enterprise Architecture

2. 2 Current Status Microsoft has announced end of support for Internet Explorer versions less than Internet Explorer 11 in January 2016. “After Jan. 12, 2016, only the most recent version of Internet Explorer available for a supported operating system will receive technical support and security updates” All ERCOT market-facing browser based applications are designed to be compatible with Internet Explorer version 8. ERCOT intends to support IE 8 for the foreseeable future.

3. 3 Compatibility Assessment Project ERCOT initiated a project to test all market facing applications for browser compatibility using IE 9, IE 10, and IE 11. Testing was done as follows: No changes were made to the application code base or systems. The applications were tested as is. Testing was done using Windows 7 and Windows 8. IE 9, IE 10, and IE 11 were tested using native as well as compatibility mode. IE 11 was also tested in “Enterprise Mode” as not all applications functioned in compatibility mode

4. 4 The Results Date to be Determined Internet Explorer 11 offered the longest support timeline & best compatibility

5. 5 Recommendation and Next Steps ERCOT will begin supporting Internet Explorer version 8 as well as Internet Explorer version 11 in “Enterprise Mode” for all market facing applications with the R5 release in September. Market participants can choose their own timelines for how and when to upgrade to Internet Explorer 11. ERCOT will publish an updated Configuration Guide specifying the required settings needed for Internet Explorer 11. While the date is not determined yet, ERCOT will end support for IE 8 in the future. A change that will have such a broad impact will be communicated to the Market well in advance before implementation.

6. 6 Questions ?