API and Web UI changes: https://airdcpp-web.github.io/2021/01/08/version-2.11.0.html

Changed:

- Let the operating system set the optimal socket write/read buffer sizes by default (can multiply per-connection transfer speeds with faster connections, https://bugs.launchpad.net/dcplusplus/+bug/1909853)
- Improve hashing speed by increasing the read buffer from 256 kilobytes to 1024 kilobytes (https://bugs.launchpad.net/dcplusplus/+bug/1909861/comments/9)
- Increase the default file write buffer from 64 kilobytes to 256 kilobytes

Fixed:

- Fix inconsistencies with filelist transfer logging

*** common changes ***
* Added support of OpenSSL >= 1.1. OpenSSL 1.0.2 is still supported too.
* Huge amount of improvements for macOS.
* Huge amount of improvements for Haiku.
* Added official support of Debian GNU/Hurd.
* Rewritten build scripts for MS Windows. Among other changes:
  - cross-compilation using MXE project (https://mxe.cc/) is used now for
    preparing of official builds
  - official Web UI for eiskaltdcpp-daemon and some MS Windows specific
    documentation are included into installers and portable builds
* Updated list of hub list servers (with most popular public hubs).
* Removed Coral CDN support since it's stopped running.
* Enable DHT by default. (Affects only new users.) In case you need you may
  change this option at any time in Preferences dialog:
  Connection --> Advanced --> Enable DHT.
* Added dht.fly-server.ru server to list of servers for bootstrapping of
  initial list of available DHT nodes.
* Delete configuration option DO_NOT_USE_MUTEX: this workaround is not required
  anymore with modern versions of compilers for MS Windows and Haiku. But part
  of this code is still used for macOS.
* Delete configuration option LOCAL_MINIUPNP.
* Delete embedded copy of miniupnpc library: it was extremely outdated and in
  any case system library is used now in builds for all supported systems.
* Stop support of miniupnpc versions older than 1.7.
* Delete update_geoip script: it does not work anymore.
* Serious code refactoring:
  — improved program stability and performance
  — stop usage of Boost libraries: all code is rewritten to C++14
  — use new C++14 features where it is possible
  — fixed notes from static code analyzers (cppcheck, clang)
*** libeiskaltdcpp ***
* Partially sync with DC++ 0.868 core in non-critical sections. The diff is
  still huge, but it was noticeably reduced.
* Add support of protocol negotiation via ALPN.
  https://forum.dcbase.org/viewtopic.php?f=55&p=4021
*** eiskaltdcpp-qt ***
* Significant improvement of Qt 5.x support. Qt 4.x is still support too.
* Added configuration option USE_PROGRESS_BARS which allow to use usual text
  labels instead of progressbars. This option is especially important for macOS
  where progressbars are unable to show any text, so a lot of information was
  hidden from users in the past.
* Added support relative paths for resources on Linux. This is necessary for
  correct work of program packaged in snap, flatpak, AppImage, etc..
* Update list of fake client tags in Favorite Hub settings.
* Improved support of nmdcs:// hubs.
* Improved setting dialog.
* Fixed reaction to left click on special search magnet links in chat.
* Added support of BitTorrent magnet links in chats. (Only correct displaying of
  links, but not support of BitTorrent protocol.)
* Added pretty icon theme "haiku". [Thanks to Gerasim Troeglazov]
*** eiskaltdcpp-gtk ***
* Fixed few minor bugs.
* Fixed build with Pango >= 1.44.
* Improved support of nmdcs:// hubs.
* Added support of BitTorrent magnet links in chats. (Only correct displaying of
  links, but not support of BitTorrent protocol.)
* This is the last release with support of GTK+ UI. It will be removed in one of
  the next versions of program. Consider switching to Qt UI now.
*** eiskaltdcpp-daemon ***
* "search.getresults" method now returns filtered results for last "search.send"
  request while all search results are stored by program. Use "search.clear" to
  free the memory from unnecessary data.
* Support of XML-RPC will be removed in one of the next releases. Consider
  switching exterior clients to JSON-RPC.