I'm pleased to announce version 1.10.0 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

This version adds the following features:

• libbson and libmongoc are now maintained in the mongo-c-driver repository,
  although they are still built as separate libraries, and libbson can still
  be used without libmongoc.
• Building libbson and libmongoc now requires CMake on all platforms. The
  Autotools build scripts ("configure" and related scripts) have been deleted.
  See the "installing" page for updated instructions.
• Additional functions for strings of known length (not necessarily null-
  terminated):
  bson_iter_find_w_len
  bson_iter_init_find_w_len
  bson_append_regex_w_len
  bson_decimal128_from_string_w_len

libmongoc

This version drops support for MongoDB 2.6 and adds the following features and bugfixes:

• libbson and libmongoc are now maintained in the mongo-c-driver repository,
  although they are still built as separate libraries, and libbson can still
  be used without libmongoc.
• Building libbson and libmongoc now requires CMake on all platforms. The
  Autotools build scripts ("configure" and related scripts) have been deleted.
  See the "installing" page for updated instructions, including the new
  ENABLE_MONGOC option and changes to the ENABLE_BSON option.
• IPv6 is now fully supported and conforms to RFC-6555. If a hostname has both
  IPv4 and IPv6 DNS records, the driver tries connecting with IPv6 first. If a
  connection can't be established after 250ms then IPv4 is tried in parallel.
  Whichever succeeds connection first cancels the other. The successful DNS
  result is cached for 10 minutes.
• If CMake is configured with ENABLE_SSL=AUTO (the default), libmongoc now
  uses native TLS libraries on Mac and Windows, and OpenSSL everywhere else.
  Before, it would search for OpenSSL on all platforms and only use native
  TLS on Mac and Windows as a fallback.
• The driver now handshakes SSL connections to multiple servers in a replica
  set or sharded cluster in parallel, so long as it uses OpenSSL or Windows
  SChannel. (SSL handshakes with Apple's Secure Transport are still serial.)
  A larger receive buffer with SChannel increases performance over slow
  connections.
• All functions that accept read concern now prohibit it, if MongoDB is too
  old to support it (MongoDB 3.0).
• Client sessions are now prohibited with unacknowledged writes.
• mongoc_collection_find_and_modify_with_opts now prohibits write concern if
  MongoDB is too old to support it (MongoDB 3.0).
• Other helper functions for commands that write, now prohibit write concern
  if MongoDB is too old to support it (pre-3.4):
  mongoc_client_read_write_command_with_opts
  mongoc_client_write_command_with_opts
  mongoc_collection_read_write_command_with_opts
  mongoc_collection_write_command_with_opts
  mongoc_database_read_write_command_with_opts
  mongoc_database_write_command_with_opts
  mongoc_collection_aggregate with $out
  mongoc_collection_drop_index_with_opts
  mongoc_collection_drop_with_opts
  mongoc_collection_rename_with_opts
  mongoc_database_drop_with_opts
  Write concern behavior is unchanged for regular CRUD functions.
• Setting a negative writeConcern level of -2 or smaller, via the "opts"
  parameter to functions that accept BSON options, is now prohibited. The
  special "w" values -2 through -4 are only used internally. The deprecated
  "w=-1" is still allowed, as a synonym for "w=0".
• The Kerberos URI option authMechanismProperties=CANONICALIZE_HOST_NAME:true
  is now implemented with the Windows Kerberos provider, SSPI.
• This repository now includes GDB and LLDB customizations for pretty-printing
  bson_t structs as JSON while debugging. See the "debugging" page.
• The internal preprocessor symbol HAVE_STRINGS_H has been renamed
  BSON_HAVE_STRINGS_H. If you maintain a handwritten bson-config.h you must
  rename this symbol.
• The following helper functions do not work with mongoc_client_session_t,
  they are deprecated in favor of running MongoDB commands directly with a
  function like mongoc_client_read_command_with_opts:
  mongoc_client_get_server_status
  mongoc_collection_stats
  mongoc_collection_validate
• mongoc_cursor_is_alive is now deprecated for mongoc_cursor_more, which is
  functionally equivalent.

Links:

• mongo-c-driver-1.10.0.tar.gz
• All the issues resolved in 1.10.0
• Documentation

Thanks to everyone who contributed to this release.

• A. Jesse Jiryu Davis
• Kevin Albertson
• Roberto C. Sánchez
• Jeremy Mikola
• Xiangyu Yao
• Jeroen Ooms
• Derick Rethans
• Kaitlin Mahar
• Pavithra Vetriselvan
• NotSpooky
• Iulian Rotaru
• Katherine Walker
• Mansuro
• Petr Písař