2019-01-24 version 3.7.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
C++
* Introduced new MOMI (maybe-outside-memory-interval) parser.
* Add an option to json_util to parse enum as case-insensitive. In the future, enum parsing in json_util will become case-sensitive.
* Added conformance test for enum aliases
* Added support for --cpp_out=speed:...
* Added use of C++ override keyword where appropriate
* Many other cleanups and fixes.
Java
* Fix illegal reflective access warning in JDK 9+
* Add BOM
Python
* Added Python 3.7 compatibility.
* Modified ParseFromString to return bytes parsed .
* Introduce Proto C API.
* FindFileContainingSymbol in descriptor pool is now able to find field and enum values.
* reflection.MakeClass() and reflection.ParseMessage() are deprecated.
* Added DescriptorPool.FindMethodByName() method in pure python (c extension alreay has it)
* Flipped proto3 to preserve unknown fields by default.
* Added support for memoryview in python3 proto message parsing.
* Added MergeFrom for repeated scalar fields in c extension (pure python already has it)
* Surrogates are now rejected at setters in python3.
* Added public unknown field API.
* RecursionLimit is also set to max if allow_oversize_protos is enabled.
* Disallow duplicate scalars in proto3 text_format parse.
* Fix some segment faults for c extension map field.
PHP
* Most issues for json encoding/decoding in the c extension have been fixed. There are still some edge cases not fixed. For more details, check conformance/failure_list_php_c.txt.
* Supports php 7.3
* Added helper methods to convert between enum values and names.
* Allow setting/getting wrapper message fields using primitive values.
* Various bug fixes.
Ruby
* Ruby 2.6 support.
* Drops support for ruby < 2.3.
* Most issues for json encoding/decoding in the c extension have been fixed. There are still some edge cases not fixed. For more details, check conformance/failure_list_ruby.txt.
* Json parsing can specify an option to ignore unknown fields: msg.decode_json(data, {ignore_unknown_fields: true}).
* Added support for proto2 syntax (partially).
* Various bug fixes.
Csharp
* More support for FieldMask include merge, intersect and more.
* Increasing the default recursion limit to 100.
* Support loading FileDescriptors dynamically.
* Provide access to comments from descriptors.
* Added Any.Is method.
* Compatible with C# 6
* Added IComparable and comparison operators on Timestamp.
Objective C
* Add ability to introspect list of enum values (#4678)
* Copy the value when setting message/data fields (#5215)
* Support suppressing the objc package prefix checks on a list of files (#5309)
* More complete keyword and NSObject method (via categories) checks for field names, can result in more fields being rename, but avoids the collisions at runtime (#5289)
* Small fixes to TextFormat generation for extensions (#5362)
* Provide more details/context in deprecation messages (#5412)
* Array/Dictionary enumeration blocks NS_NOESCAPE annotation for Swift (#5421)
* Properly annotate extensions for ARC when their names imply behaviors (#5427)
* Enum alias name collision improvements (#5480)
2018-07-27 version 3.6.1 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)