ByteDance's open-source super agent harness (82k+ stars). 2.0 is a ground-up rewrite sharing no code with 1.x: sub-agents, extensible skills, sandbox and file system, long-term memory, session goals, plus Manual Context Compaction that hands context management back to the operator. Positioning lifted from a deep-research framework to a runtime for any task. Not benchmarked by us; graded needs-reproduction.