Qtractor 0.5.7 发布，多轨音序生成器

Qtractor 0.5.7 支持 LV2 选项和 Buf-size 扩展，其余还包括：

• Location markers (per bar) and MIDI clip editor value/velocities line-drawing are finally a reality.
• Punch in/out and loop recording are now mutually compatible operational modes.
  
• LV2 UI parameter communication is now properly untangled, especially targeted at GTK+ based plug-in GUIs.
  
• At last, libSLV2 support has been dropped as a build option, now honoring libLILV for good

Qtractor 是一个音频/MIDI 的多轨音序生成器，采用C++编写，支持 Linux 系统。