Implementable right now (but not necessarily important), with caveats
(unavailable components that will limit what can be implemented right
away), in order in which they will likely be done:
* TESTING-TESTBED [Nate]
* SETUP
* DV [Nate]
* TBENCH
* TRACEKIT
* FRAGMENTATION [Ji Lu]
* HTTP transport
* MySQL / Postgres plugins (datastore, datacache)
* UPNP [Milan]
* ARM [Safey]
* FS [Christian]

0.9.0pre0:
* TRANSPORT:
  - TCP not used bi-directionally (especially important also for PONG!)
    Need a way for plugin to tell to service that it can *reliably* transmit
    PONGs.  Need *good* way to ensure only one (plugin) session is active at 
    any given point in time; need systematic way to periodically probe latency/
    transport cost changes
  - disconnect notifications from TCP not always as nice as we might want
    them to be (but how can we do this cleanly given that UDP is connectionless?)
  - hostlist testcase shows that (randomly) we jump to an address that
    seems to be a plugin function *after* the plugin has been unloaded
    (directly from scheduler); check that *all* plugin tasks are cancelled
    after plugin is unloaded! (need better testcases for that...)
  - implement transport API to pretty-print transport address 
    + transport_api extension (API extension!)
    + service-transport extension (protocol extension)
  - implement gnunet-transport (transport configurator / tester)
  - instantly filter addresses from *other* peers that 
    are *equal* to our own address + port (i.e., localhost:2086).  We 
    no longer filter those for outgoing (helps with loopback testing
    and keeps the code clean), but we should filter strictly *impossible*
    incoming addresses!  This is for efficiency, not correctness.
  - UPnP-based IP detection
    (Note: build library always, build service when libxml2/etc. are available)
  - We currently are happy to take any address told to us in a WELCOME
    to our set of addresses; we should have some minimal threshold-based
    scheme, limiting both the total number of addresses that we accept 
    this way as well as requiring multiple confirmations; also, we
    should possibly try to confirm that the given address works for
    us ourselves (loopback-style) before adding it to the list
    [SECURITY issue]
    + we may be able to simplify WELCOME messages (no need to add 
      addresses there anymore, but may help to learn them there anyway...).
    + we probably want some kind of voting/counting for learning IP addresses
      (maybe including IP addresses in ads proportional to how often others
       report them? we at least need some protection against >64k HELLOs!),
    + provide a way to give the user a list of "learned" IP addresses and
      a way to easily "veto" addresses off the list!
      => If MiM attacker uses vetoed address, blacklist the specific IP for
         the presumed neighbour!
  - [./transport/gnunet-service-transport.c:173]: (style) struct or union member 'TransportPlugin::rebuild' is never used
  - [./transport/plugin_transport_tcp.c:391]: (style) struct or union member 'Plugin::address_update_task' is never used
* FS:
  - [./fs/gnunet-service-fs.c:208]: (style) struct or union member 'LocalGetContext::results_bf_size' is never used
  - [./fs/gnunet-service-fs.c:501]: (style) struct or union member 'PendingRequest::used_pids_size' is never used
  - [./fs/gnunet-service-fs.c:654]: (style) struct or union member 'ConnectedPeer::last_client_replies' is never used
  - [./fs/gnunet-service-fs.c:669]: (style) struct or union member 'ConnectedPeer::avg_delay' is never used
  - [./fs/gnunet-service-fs.c:675]: (style) struct or union member 'ConnectedPeer::avg_priority' is never used
  - [./fs/gnunet-service-fs.c:688]: (style) struct or union member 'ConnectedPeer::pending_requests' is never used
  - [./fs/gnunet-service-fs.c:694]: (style) struct or union member 'ConnectedPeer::last_p2p_replies_woff' is never used
  - [./fs/gnunet-service-fs.c:700]: (style) struct or union member 'ConnectedPeer::last_client_replies_woff' is never used
* CORE:
  - SET_KEY is triggered every 2.5 minutes (after session is up); should
    just do PING (not SET_KEY + PING)
  - "Forcing disconnect of XXX due to inactivity" -- can happen every few MS!?
    (disconnect does not really succeed, or what?)
* TOPOLOGY:
  - needs more testing (especially F2F topology)
  - needs to re-try connecting after disconnect (currently, it
    initially triggers a connection request, but if that connection
    fails / goes down, it does not retry in a timely fashion;
    cause seems to be the 'blacklist_after_attempt' being set to 1h,
    which is rather long -- and should probably be adjusted based on
    the number of connections / known peers)
  - If the topology daemon crashes, peers that were put on the
    blacklist with transport will never be removed from it (until
    transport service dies); we should use the blacklist notification
    API to learn about the exact set of blacklisted peers at all times
    (FIXME: the transport_api implementation of blacklisting
     also does not work nicely for this since it won't let us know about
     disconnect-reconnect events and the implicit whitelisting
     that might happen here; that's not so bad since we will
     re-blacklist on pre-connect attempts anyway, so this is 
     a minor issue).
  - the code uses the term 'blacklist' for both peers that are forbidden
    to connect (i.e. F2F mode) as well as peers that we currently
    won't try to actively connect to ourselves (since we just tried);
    This is confusing.  We need two distinct terms.
  - move code to use hash table instead of linked list
  - instead of periodically discarding blacklisted entries,
    simply add task that is triggered at the right time (earlier free,
    more balanced load)
  - check if new HELLO learned is different from old HELLO
    before resetting entire state!
* UTIL:
  - trust: need *fast* way to check/update trust in peers
           (async peerinfo would not be right)
  - scheduler should change OS process priority based on task priority;   
    should make better use of task priorities in general
  - only connect() sockets that are ready (select()) [Nils]
    [On W32, we need to select after calling socket before
     doing connect etc.]
* STATISTICS:
  - synchronous/asynchronous API (& implementation) is not nice;
    => provide notification-based API
  - does not seem to work with timeouts (especially if service is not running)
* DATACACHE:
  - add stats (# bytes available, # bytes used, # PUTs, # GETs, # GETs satisfied)
* ARM:
  - need to get rid of synchronous API for service starts (cause all kinds of problems)
    [=> eliminate for need to tell ARM about service starts most of the time!] [Safey]
  - better tracking of which config changes actually need to cause process restarts by ARM.
  - listen for requests to discover dependencies between services (and avoid
    having to explicitly program start requests)
  - better crash management (attach debugging support, capture and analyze
    debug output, detect random vs. deterministic crashes)
  - shutdown sequence?
* HELLO:
  - need function to test "equivalency" of HELLOs; use in topology!
* FS:
  - GAP improvements:
    + active reply route caching design & implementation of service,
      gap extension!
  - gnunet-publish cannot be aborted using CTRL-C
  - gnunet-publish segfaults if file does not exist
  - on some systems, keyword search does not find locally published content
    (need testcase of command-line tools!)
  - 2-peer download is still too slow (why?)
* Module features to implement:
  - advanced FS API parts
    + namespaces: fundamental namespace API
    + search: SBlocks, KSBlocks, probes, notify FS-service of known results
    + collection
    + location URIs (publish, search, download)
    + persistence support (publish, unindex, search, download)
    + indexing: index-failure-cleanup
    + download: management/bounding of parallel downloads (for recursive dl.)
    + datastore reservation (publishing)
    + gnunet-publish (URI args)
    + gnunet-download (directory)
    + gnunet-search (options, incl. namespace search)
    + gnunet-download (many options)
    + gnunet-directory (man page, options)
    + gnunet-pseudonym (all of it)
    + gnunet-service-fs (remove failing on-demand blocks, stats, hot-path routing, load-based routing, nitpicks)
    + datastore: do active migration support here?   
  - implement adv. FS testcases 
    + getopt API
    + insert: sblocks, loc uris
    + download: loc uris
    + search: sblocks, skblocks, loc uris
    + namespaces
    + collection
  - implement FS performance tests (needs TESTING)
    + insert
    + download
    + search
    + unindex
  - non-anonymous FS service (needs DHT)
    + basic DHT integration
    + CS-DHT-functions (DHT-put of LOC)
    + P2P-functions (DHT-get)
  - setup (RC-pre0)
    + default generation
    + need to settle basic design; do we want to keep guile?
  - testing (RC-pre0)
    + modify configuration to allow controlling connections for non-local starts
    + testbed creation with topology (needs working F2F topology) [Nate]
    + testbed with churn [Nate]
    + implement library for distributed testing [Nate]
    + implement testcases for distributed testing [Nate]
    + test basic peer re-configure [Nate]
    + test topology creation [Nate]
    + test churn generation [Nate]
* TESTING:
  - consider changing API for peer-group termination to 
    call continuation when done
* WWW:
  - Get IPv6 hooked up
  - change DNS

0.9.0pre1:
* Module features to implement:
  - tbench (RC-pre1)
    + good to have for DV evaluation!
  - DV (RC-pre1)
    + write DV API 
    + implement DV service [Nate & CG]
    + implement DV library [Nate]
    + implement DV transport plugin [Nate & CG]
    + implement testcases [Nate]
    + implement performance tests [Nate]
* SETUP:
  - design & implement new setup tool
* GUIs to implement:
  - gtk (RC-pre1)
    + how to integrate scheduler with GTK event loop!
* HOSTLIST:
  - 'server' uses 'GNUNET_PEERINFO_iterate', should probably switch to notification API
    (for more instant / up-to-date hostlists at lower cost) [OPTIMIZATION]

0.9.0pre2:
* Module features to implement:
  - tracekit (RC-pre2)
    + good to have for DV/DHT evaluation!
  - DHT (RC-pre2)
    + implement DHT service (needs DV, DATACACHE)
    + implement DHT library
    + implement testcases
    + implement performance tests
* GUIs to implement:
  - fuse (RC-pre2)
* Plugins to implement:
  - UDP backend (RC-pre2)
    + Fragmentation library 
    + actual plugin
  - HTTP backend (RC-pre2)

0.9.0pre3:
* GUIs to implement:
  - qt (RC-pre3)
    + see discussions @ FISL about integration with event loop!
* Determine RC bugs and fix those!

0.9.0:
* Documentation
  - update man pages
  - update webpage documentation
* new webpage:
  - expand bibliography
  - convert documentation pages to books
  - update books (especially for developers)
  - create good Drupal theme for GNUnet
  - make a NICE download page and figure out how to 
    enable developers to publish TGZs nicely
  - port "contact" page
  - add content type for "todo" items?
  - DNS activation
* Plugins to implement:
  - MySQL database backends
    + datacache
    + datastore
  - Postgres database backends
    + datacache
    + datastore
  - vpn
* Determine RC bugs and fix those!


0.9.x:
* Plugins to implement:
  - SMTP transport backend
  - HTTPS transport backend
    + improved HTTPS support in MHD
    + actual plugin
* Remove KBlocks in gnunet-unindex (see discussion with Kenneth Almquist on gnunet-devs in 9/2009)
* Allow checking of presence of search results and/or content via command-line tools
  (add options to gnunet-search / gnunet-download to limit search to local peer)
* STATISTICS:
  - should use BIO instead of mmap
* PEERINFO:
  - expire 'ancient' HELLOs (those without valid addresses AND that 
    we have not 'used' (for their public keys) in a while; need a way
    to track actual 'use')
  - make sue we also trigger notifications whenever HELLOs expire