2.0.0

Added

• A fixed 256-color palette, now the default: 16 Minecraft hues in 16 shades
  each, like a DOS game's own palette.
• The stock VGA palette, as an option.
• Colormap lighting (default on): textures use only palette colors and
  shading steps down each color's ramp, like Doom and Quake.

Changed

• Texture mapping defaults to Quake-style subdivision: perspective-correct
  every 16 pixels and linear in between, a subtle wobble instead of heavy
  warping. Full affine and perspective-correct are options (Texture Mapping).
• Textures pick their mipmap for the 320×200 output, so distant surfaces
  shimmer much less.
• Rain and particles use the generic textured program; rain now wobbles like
  other geometry.
• Fog and texture mapping take the pixel position from the vertex shader
  instead of reconstructing it per pixel. Same look, less work.
• Viewmodel Dithering is now a strength slider; 0 turns it off.
• The option menu is trimmed (see Removed). Saved settings for removed or
  renamed options reset to their defaults.

Fixed

• Surfaces seen at a very steep angle no longer smear, or show other blocks'
  textures inside them or as lines along their edges, with subdivided
  mapping.
• 1.21.x flora (bush, eyeblossoms, dry grass…) billboards again; it broke in 1.0.3.
• Copper Age chains and lanterns now actually billboard.
• Stained glass, ice and other translucents no longer darken at night; only water does.

Removed

• Palette Mode and Bypass options, replaced by Palette (Off, Ramp, VGA,
  RGB332, 6x6x6).
• Affine Mapping, Near Distance and Fade Range options (replaced by Texture
  Mapping).
• Fog Tuning toggle, Start/End Offset and Minimum Range options. Fog keeps
  its Start, End and Density scales; 1.00 is vanilla.
• Dither Strength option (merged into Viewmodel Dithering).
• OptiFine from the listed loaders. It was never supported.
• Programs that duplicated their Iris fallback, and an unused one. No visual change.