ArduinoJson 7.3.0
* Fix support for NUL characters in `deserializeJson()`
* Make `ElementProxy` and `MemberProxy` non-copyable
* Change string copy policy: only string literal are stored by pointer
* `JsonString` is now stored by copy, unless specified otherwise
* Replace undocumented `JsonString::Ownership` with `bool`
* Rename undocumented `JsonString::isLinked()` to `isStatic()`
* Move public facing SFINAEs to template declarations

ArduinoJson 7.2.1
* Forbid `deserializeJson(JsonArray|JsonObject, ...)` (issue #2135)
* Fix VLA support in `JsonDocument::set()`
* Fix `operator[](variant)` ignoring NUL characters

ArduinoJson 7.2.0
* Store object members with two slots: one for the key and one for the value
* Store 64-bit numbers (`double` and `long long`) in an additional slot
* Reduce the slot size (see table below)
* Improve message when user forgets third arg of `serializeJson()` et al.
* Set `ARDUINOJSON_USE_DOUBLE` to `0` by default on 8-bit architectures
* Deprecate `containsKey()` in favor of `doc["key"].is<T>()`
* Add support for escape sequence `\'` (issue #2124)

ArduinoJson 7.1.0
* Add `ARDUINOJSON_STRING_LENGTH_SIZE` to the namespace name
* Add support for MsgPack binary (PR #2078 by @Sanae6)
* Add support for MsgPack extension
* Make string support even more generic (PR #2084 by @d-a-v)
* Optimize `deserializeMsgPack()`
* Allow using a `JsonVariant` as a key or index (issue #2080)

ArduinoJson 7.0.4
* Make `JSON_STRING_SIZE(N)` return `N+1` to fix third-party code (issue #2054)

ArduinoJson 7.0.3
* Improve error messages when using `char` or `char*` (issue #2043)
* Reduce stack consumption (issue #2046)
* Fix compatibility with GCC 4.8 (issue #2045)

ArduinoJson 7.0.2
* Fix assertion `poolIndex < count_` after `JsonDocument::clear()` (issue #2034)

ArduinoJson 6.21.5
* Fix warning `function returns incomplete class type` on IAR (issue #2001)
* Fix `volatile bool` serialized as `1` or `0` instead of `true` or `false` (issue #2029)
* Remove unused files in the PlatformIO package

ArduinoJson 7.0.1
* Fix "no matching function" with `JsonObjectConst::operator[]` (issue #2019)
* Remove unused files in the PlatformIO package
* Fix `volatile bool` serialized as `1` or `0` instead of `true` or `false` (issue #2029)

ArduinoJson 7.0.0
* Remove `BasicJsonDocument`
* Remove `StaticJsonDocument`
* Add abstract `Allocator` class
* Merge `DynamicJsonDocument` with `JsonDocument`
* Remove `JSON_ARRAY_SIZE()`, `JSON_OBJECT_SIZE()`, and `JSON_STRING_SIZE()`
* Remove `ARDUINOJSON_ENABLE_STRING_DEDUPLICATION` (string deduplication cannot be disabled anymore)
* Remove `JsonDocument::capacity()`
* Store the strings in the heap
* Reference-count shared strings
* Always store `serialized("string")` by copy (#1915)
* Remove the zero-copy mode of `deserializeJson()` and `deserializeMsgPack()`
* Fix double lookup in `to<JsonVariant>()`
* Fix double call to `size()` in `serializeMsgPack()`
* Include `ARDUINOJSON_SLOT_OFFSET_SIZE` in the namespace name
* Remove `JsonVariant::shallowCopy()`
* `JsonDocument`'s capacity grows as needed, no need to pass it to the constructor anymore
* `JsonDocument`'s allocator is not monotonic anymore, removed values get recycled
* Show a link to the documentation when user passes an unsupported input type
* Remove `JsonDocument::memoryUsage()`
* Remove `JsonDocument::garbageCollect()`
* Add `deserializeJson(JsonVariant, ...)` and `deserializeMsgPack(JsonVariant, ...)` (#1226)
* Call `shrinkToFit()` in `deserializeJson()` and `deserializeMsgPack()`
* `serializeJson()` and `serializeMsgPack()` replace the content of `std::string` and `String` instead of appending to it
* Replace `add()` with `add<T>()` (`add(T)` is still supported)
* Remove `createNestedArray()` and `createNestedObject()` (use `to<JsonArray>()` and `to<JsonObject>()` instead)

ArduinoJson 6.21.4
* Fix error `'std::string' has not been declared` (issue #1967)
* Fix error `'std::string_view' has not been declared` (issue #1967)
* Fix error `no instance of overloaded function...` on recent IAR compilers (issue #2001)

ArduinoJson 6.21.3
* Fix compatibility with the Blynk libary (issue #1914)
* Fix double lookup in `to<JsonVariant>()`
* Fix double call to `size()` in `serializeMsgPack()`
* Include `ARDUINOJSON_SLOT_OFFSET_SIZE` in the namespace name
* Show a link to the documentation when user passes an unsupported input type

ArduinoJson 6.21.2
* Fix compatibility with the Zephyr Project (issue #1905)
* Allow using PROGMEM outside of Arduino (issue #1903)
* Set default for `ARDUINOJSON_ENABLE_PROGMEM` to `1` on AVR

ArduinoJson 6.21.1
* Double speed of `DynamicJsonDocument::garbageCollect()`
* Fix compatibility with GCC 5.2 (issue #1897)

ArduinoJson 6.21.0
* Drop support for C++98/C++03. Minimum required is C++11.
* Remove `ARDUINOJSON_NAMESPACE`; use `ArduinoJson` instead.
* Make string support generic (issue #1807)

ArduinoJson 6.20.1
* Remove explicit exclusion of `as<char*>()` and `as<char>()` (issue #1860)

ArduinoJson 6.20.0
* Add `JsonVariant::shallowCopy()` (issue #1343)
* Fix `9.22337e+18 is outside the range of representable values of type 'long'`
* Fix comparison operators for `JsonArray`, `JsonArrayConst`, `JsonObject`, and `JsonObjectConst`
* Fix lax parsing of `true`, `false`, and `null` (issue #1781)
* Remove undocumented `accept()` functions
* Rename `addElement()` to `add()`
* Remove `getElement()`, `getOrAddElement()`, `getMember()`, and `getOrAddMember()`
* Remove undocumented `JsonDocument::data()` and `JsonDocument::memoryPool()`
* Remove undocumented `JsonArrayIterator::internal()` and `JsonObjectIterator::internal()`
* Rename things in `ARDUINOJSON_NAMESPACE` to match the public names
* Add documentation to most public symbols
* Remove support for naked `char` (was deprecated since 6.18.0)

ArduinoJson 6.19.4
* Add `ElementProxy::memoryUsage()`
* Add `MemberProxy::memoryUsage()` (issue #1730)
* Add implicit conversion from `JsonDocument` to `JsonVariant`
* Fix comparisons operators with `const JsonDocument&`

ArduinoJson 6.19.3
* Fix `call of overloaded 'String(const char*, int)' is ambiguous`
* Fix `JsonString` operator `==` and `!=` for non-zero-terminated string
* Fix `-Wsign-conversion` on GCC 8 (issue #1715)
* MessagePack: serialize round floats as integers (issue #1718)

ArduinoJson 6.19.2
* Fix `cannot convert 'pgm_p' to 'const void*'` (issue #1707)