+* better test cases, make faster by reusing more setup
+ code across tests
+
+* large mbox/Maildir/MH/NNTP spool import (in lei, but not
+ for public-facing inboxes)
+
+* MH import support (read-only, at least)
+
+* Read-only WebDAV interface to the git repo so it can be mounted
+ via davfs2 or fusedav to avoid full clones.
+ davfs2 needs Range: request support for this to be feasible:
+ https://savannah.nongnu.org/bugs/?33259
+ https://savannah.nongnu.org/support/?107649
+
+* Contribute something like IMAP IDLE for "git fetch".
+ Inboxes (and any git repos) can be kept up-to-date without
+ relying on polling.
+
+* Improve bundle support in git to make it cheaper to host/clone
+ with dumb HTTP(S) servers.
+
+* Expose targeted reindexing of individual messages.
+ Sometimes an indexing bug only affects a handful of messages,
+ so it's not worth the trouble of doing a full reindex.
+
+* code repository integration (cgit: done, TODO: gitweb, etc...)
+
+* migration path to v2 without breaking v1 "git fetch" cronjobs
+
+* imperfect scraper importers for obfuscated list archives
+ (e.g. obfuscated Mailman stuff, Google Groups, etc...)
+
+* improve performance and avoid head-of-line blocking on slow storage
+ (done for most git blob retrievals, Xapian needs work)
+
+* HTTP(S) search API (likely JMAP, but GraphQL could be an option)
+ It should support git-specific prefixes (dfpre:, dfpost:, dfn:, etc)
+ as extensions. If JMAP, it should have HTTP(S) analogues to
+ various IMAP extensions.
+
+* search across multiple inboxes, or admin-definable groups of inboxes
+
+ This will require a new detached Xapian index that can be used in
+ parallel with existing per-inbox indices. Using ->add_database
+ with hundreds of shards is unusable in current Xapian as of
+ August 2020 (acknowledged by Xapian upstream).
+
+* scalability to tens/hundreds of thousands of inboxes
+
+ - pagination for WwwListing
+
+ - inotify-based manifest.js.gz updates
+
+ ...
+
+* lei - see %CMD in lib/PublicInbox/LEI.pm
+
+* make "git cat-file --batch" detect unlinked packfiles so we don't
+ have to restart processes (very long-term)
+
+* support searching based on `git-patch-id --stable` to improve
+ bidirectional mapping of commits <=> emails
+
+* linter to check validity of config file
+
+* linter option and WWW endpoint to graph relationships and flows
+ between inboxes, addresses, Maildirs, coderepos, newsgroups,
+ IMAP mailboxes, etc...
+
+* pygments support - via Python script similar to `git cat-file --batch'
+ to avoid startup penalty. pygments.rb (Ruby) can be inspiration, too.
+
+* highlighting + linkification for "git format-patch --interdiff" output
+
+* highlighting for "git format-patch --range-diff" output
+ (linkification is too expensive, as it requires mirroring)
+
+* support UUCP addresses for legacy archives
+
+* decode (skip indexing of) base-85 binary patches to avoid false-positives