Version 4.0, released in 1999, marked a significant milestone for Adobe Reader. This version introduced a new feature called "PDF 1.4," which enabled support for JavaScript, digital signatures, and layers. Additionally, version 4.0 included a revamped user interface and improved performance.
, meaning they no longer receive security patches or technical support. Adobe Help Center Version Series Support Status Key Era Features Reader 9 & Earlier End of Support Last versions for legacy systems like Windows XP. Reader X (10) & XI (11) End of Support Introduced "Protected Mode" (sandboxing) for security. Acrobat Reader DC (2015-Present) versions of adobe reader