The best replacement for opengl is directx.

The best alternatives to opengl are rated as following:
★★★★★  directx
★★★★  direct3d
★★  d3d
★★  sdl
★★  opencl
★★  cuda
★  opengl es
★  directx runescape
★  directx google earth
★  directx 11
★  directx 10
★  webgl
★  mantle
★  qt
★  sprite kit
★  directx osu
★  unity
  spritekit
  dx11
  xrender
  opencv
  d3d counter strike
  dx10
  canvas android
  directx 12
  openvg
  3d
  software runescape
  gdi
  directx 9
  directdraw
  libgdx
  game engine
  direct 3d
  glut
  cocos2d
  java3d
  directx awesomenauts
  direct x

Your alternative for opengl is not listed? Suggest!
Speaking about opengl, one probably shouldn't forget about sdl.

Other search terms related to opengl and their ratings are:
★★★★★ sdl
★★★★★ c++
★★★ qt
★★★ visual c++
★★ glew
★★ sdl2
★ sfml
★ opencv
★ mfc
★ hardware acceleration
★ opencl
vc++
glsl
dev c++
gtk
You have in mind a companion for opengl and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of opengl in all years. Click on graph for more.
opengl
directx
direct3d