What are some alternatives?
When comparing SFML and Allegro, you can also consider the following products
SDL - Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level...
MonoGame - MonoGame is an open source implementation of the Microsoft XNA 4 Framework.
Unity - The multiplatform game creation tools for everyone.
OpenGL - OpenGL is the premier environment for developing portable, interactive 2D and 3D graphics...
Vulkan - Vulkan is a new generation graphics and compute API that provides high-efficiency, cross-platform access to modern GPUs used in a wide variety of devices from PCs and consoles to mobile phones and embedded platforms.