Developers implement accessibility in web applications by adhering to established web accessibility standards, such as WCAG (Web Content Accessibility Guidelines). This involves creating designs that accommodate users with disabilities, ensuring content is perceivable, operable, understandable, and robust. Key practices include using proper semantic HTML, providing alternative text for images, and ensuring keyboard navigability. Developers also conduct accessibility testing to identify barriers that may hinder user interaction. By prioritizing accessibility, web applications become more inclusive, allowing a broader audience to engage with content effectively, thus supporting diversity and equal access in the digital space.