Thunderbird 6.0, etc.

In a process driven by the Firefox developers, Mozilla has substantially redesigned their release process [1]. Thus, there will no longer be parallel branches after Firefox 3.6 and Thunderbird 3.1 have reached their end of support. Instead, each release will have a full version bump even if there are no or marginal feature changes (i.e., Firefox 5.0 will be the stability update for 4.0.1, then 6.0 will be the update for 5.0, etc.) [2]. Only in quick "firedrill" follow-up releases which become necessary shortly after a release to fix a missed issue, a minor "dot" release will be issued.

Thunderbird decided to follow that pattern, and in the process to re-align its numbers with Firefox again [3]. Consequently, the "Miramar" branch has been bumped from 3.3 to 5.0, and the next release after 5.0 will be Thunderbird 6.0 (formerly 3.4) around the same time when Firefox 6.0 is released. It yet has to be seen how this process turns out in practical terms, especially with respect to add-on compatibility as a stable API is no longer given as it was previously assured during the lifetime of a branch.

The user-facing changes between Thunderbird 5.0 and Thunderbird 6.0 should be close to none, given that there were only two weeks (May 10 vs. May 24, 2011) between the string and feature freezes of these two versions, even if the time between those two releases is longer.

Changes in individual updates

In this section, updates to the previous articles should be added along with a reference to the respective section in that article which they obsolete. This is intended to keep track of any incremental changes as development of new features and bug fixes proceed.

Updates for Thunderbird 6.0

(none yet)

Updates for Thunderbird 7.0

relates to section: Thunderbird 5.0 - New Features and Changes#Font rendering and performance issues

The options to influence ClearType/Direct2D have been extended with the following preferences, thus allowing a better fine-tuning of font display [4], [5], [6]:

• gfx.font_rendering.cleartype_params.gamma - between 1000 and 2200 and describes a luminance curve, the value depends on the physical screen characteristics
• gfx.font_rendering.cleartype_params.enhanced_contrast - 0 to 1000, the default 50 should work for black on white
• gfx.font_rendering.cleartype_params.cleartype_level - 0 to 100 (percent?), defaults to 100, where 50 is recommended for a compromise in fringe effects
• gfx.font_rendering.cleartype_params.pixel_structure - 0 to 2, defaults to 0 = "flat" but may be set to 2 for BGR monitors (this seems to influence the shift between red and blue colors)
• gfx.font_rendering.cleartype_params.rendering_mode - the value 0 means default handling depending on font and size, other values:
  1. aliased
  2. GDI Classic
  3. GDI Natural Widths
  4. Natural
  5. Natural Symmetric

The defined defaults for all preferences is "-1" and implies the stated default behavior.

Another preference gfx.font_rendering.cleartype_params.force_gdi_classic_for_families contains a comma-separated list of fonts for which GDI classic mode will be used, up to a size specified in the .force_gdi_classic_max_size preference and only if .cleartype_params.rendering_mode doesn't specify a non-default behavior.

See also

• Thunderbird 5.0 - New Features and Changes
• An explanation about versions and builds for testing (TB Builds forum)