Inactive proposals are proposals that at one point were presented to the committee but were subsequently abandoned, withdrawn, or rejected.
Stage 0 (Strawperson)
Stage 0 proposals are either planned to be presented to the committee by a TC39 champion, or they have been presented to the committee and not rejected definitively, but have not yet achieved any of the criteria to get into stage 1.
Stage 1 (Proposal)
Stage 1 proposals represent problems that the committee is interested in spending time exploring solutions to. This stage is where a formal proposal that describes a specific problem and solution is created and reviewed.
Stage 2 (Draft)
Stage 2 precisely describes the syntax and semantics using formal spec language. It indicates that the committee expects these features to be developed and eventually included in the standard.
Stage 3 (Candidate)
Stage 3 indicates that the solution is complete and no further work is possible without implementation experience, significant usage and external feedback.
Stage 4 (Finished)
Stage 4 indicates that the addition is ready for inclusion in the formal ECMAScript standard.