Horde3D

Horde3D recently gained hardware support for the linearization of sRGB textures, which is great. But currently in order to convert it back into sRGB you have to do it with the use of shaders, which has a few problems. Firstly blending will computed incorrectly as it is performed on non-linear color space, and secondly there is a small performance hit.

A solution to this problem is to make framebuffers sRGB-aware with the use of EXT_framebuffer_sRGB.
This would fix both problems as the conversion back to sRGB is done in hardware so it's practically free in terms of performance and also if blending is enabled the texture is converted back to linear color space before blending and the result of the blend is then gamma-corrected.

If you use an FP16 buffer to store your values in linear space, you won't have problems with incorrect blending (supposed you have SM3) and you have enough precision (even more than in sRGB space). When respecting gamma, probably you will want to use HDR as well and for that FP16 is a reasonable solution on PC. BTW, the sRGB framebuffer extension is not available everywhere and unfortunately you can't assume that the writes are for free.