A Substance material from Substance Source supports both the metallic/roughness and specular/glossiness workflows.
Depending on the renderer, you may be able to use these outputs directly or you may need to convert the output types. Custom Substance materials or materials you download from Substance Share may or may not have the appropriate outputs.
It's important to understand the type of material inputs your render will except so that you can best utilize the Substance material. For example, with Arnold 5 you can use the metallic/roughness outputs directly. However, with a Renderman's pxrSurface, you will need to convert the basecolor/metallic outputs to diffuse/specular maps.
The Substance toolset can author both metal/rough and spec/gloss textures, but the metallic/roughness workflow is used by default.
With the Substance toolset, you can export bitmaps or you can use the Substance plugins. A Substance plugin will automatically create a material for you to use with your renderer.