If you are using CS5 for specific legacy tools, it introduced several landmark features: Shape Builder Tool
Released in April 2010, Adobe Illustrator CS5 represented a significant milestone in the evolution of vector graphics editing. It introduced powerful features such as the Bristle Brush for realistic painting, the Shape Builder tool for intuitive merging and subtracting of shapes, and a refined anti-aliasing engine for better on-screen text display. For graphic designers, illustrators, and typographers, CS5 became a reliable workhorse that balanced performance with innovation. Even over a decade later, many professionals nostalgically recall its stability and clean interface. Yet, the continued demand for an "Adobe Illustrator CS5 portable" version reveals a darker, ongoing issue in the software industry: piracy and the allure of unsupported, cracked applications. Adobe Illustrator CS5 portable