diff --git a/CHANGES.txt b/CHANGES.txt
index 1164583645..ccc8ff9439 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,3 +1,111 @@
+2017-04-05 version 3.3.0 (C++/Java/Python/PHP/Objective-C/C#/Ruby/JavaScript)
+  Planned Future Changes
+  * There are some changes that are not included in this release but are
+    planned for the near future:
+      - Preserve unknown fields in proto3: please read this doc:
+
+          https://docs.google.com/document/d/1KMRX-G91Aa-Y2FkEaHeeviLRRNblgIahbsk4wA14gRk/view
+
+        for the timeline and follow up this github issue:
+
+          https://github.com/google/protobuf/issues/272
+
+        for discussion.
+      - Make C++ implementation C++11 only: we plan to require C++11 to build
+        protobuf code starting from 3.4.0 or 3.5.0 release. Please join this
+        github issue:
+
+          https://github.com/google/protobuf/issues/2780
+
+        to provide your feedback.
+
+  C++
+  * Fixed map fields serialization of DynamicMessage to correctly serialize
+    both key and value regardless of their presence.
+  * Parser now rejects field number 0 correctly.
+  * New API Message::SpaceUsedLong() that’s equivalent to
+    Message::SpaceUsed() but returns the value in size_t.
+  * JSON support
+    - New flag always_print_enums_as_ints in JsonPrintOptions.
+    - New flag preserve_proto_field_names in JsonPrintOptions. It will instruct
+      the JSON printer to use the original field name declared in the .proto
+      file instead of converting them to lowerCamelCase when printing JSON.
+    - JsonPrintOptions.always_print_primtive_fields now works for oneof message
+      fields.
+    - Fixed a bug that doesn’t allow different fields to set the same json_name
+      value.
+    - Fixed a performance bug that causes excessive memory copy when printing
+      large messages.
+  * Various performance optimizations.
+
+  Java
+  * Map field setters eagerly validate inputs and throw NullPointerExceptions
+    as appropriate.
+  * Added ByteBuffer overloads to the generated parsing methods and the Parser
+    interface.
+  * proto3 enum's getNumber() method now throws on UNRECOGNIZED values.
+  * Output of JsonFormat is now locale independent.
+
+  Python
+  * Added FindServiceByName() in the pure-Python DescriptorPool. This works only
+    for descriptors added with DescriptorPool.Add(). Generated descriptor_pool
+    does not support this yet.
+  * Added a descriptor_pool parameter for parsing Any in text_format.Parse().
+  * descriptor_pool.FindFileContainingSymbol() now is able to find nested
+    extensions.
+  * Extending empty [] to repeated field now sets parent message presence.
+
+  PHP
+  * Added file option php_class_prefix. The prefix will be prepended to all
+    generated classes defined in the file.
+  * When encoding, negative int32 values are sign-extended to int64.
+  * Repeated/Map field setter accepts a regular PHP array. Type checking is
+    done on the array elements.
+  * encode/decode are renamed to serializeToString/mergeFromString.
+  * Added mergeFrom, clear method on Message.
+  * Fixed a bug that oneof accessor didn’t return the field name that is
+    actually set.
+  * C extension now works with php7.
+  * This is the first GA release of PHP. We guarantee that old generated code
+    can always work with new runtime and new generated code.
+
+  Objective-C
+  * Fixed help for GPBTimestamp for dates before the epoch that contain
+    fractional seconds.
+  * Added GPBMessageDropUnknownFieldsRecursively() to remove unknowns from a
+    message and any sub messages.
+  * Addressed a threading race in extension registration/lookup.
+  * Increased the max message parsing depth to 100 to match the other languages.
+  * Removed some use of dispatch_once in favor of atomic compare/set since it
+    needs to be heap based.
+  * Fixes for new Xcode 8.3 warnings.
+
+  C#
+  * Fixed MapField.Values.CopyTo, which would throw an exception unnecessarily
+    if provided exactly the right size of array to copy to.
+  * Fixed enum JSON formatting when multiple names mapped to the same numeric
+    value.
+  * Added JSON formatting option to format enums as integers.
+  * Modified RepeatedField<T> to implement IReadOnlyList<T>.
+  * Introduced the start of custom option handling; it's not as pleasant as it
+    might be, but the information is at least present. We expect to extend code
+    generation to improve this in the future.
+  * Introduced ByteString.FromStream and ByteString.FromStreamAsync to
+    efficiently create a ByteString from a stream.
+  * Added whole-message deprecation, which decorates the class with [Obsolete].
+
+  Ruby
+  * Fixed Message#to_h for messages with map fields.
+  * Fixed memcpy() in binary gems to work for old glibc, without breaking the
+    build for non-glibc libc’s like musl.
+
+  Javascript
+  * Added compatibility tests for version 3.0.0.
+  * Added conformance tests.
+  * Fixed serialization of extensions: we need to emit a value even if it is
+    falsy (like the number 0).
+  * Use closurebuilder.py in favor of calcdeps.py for compiling JavaScript.
+
 2017-01-23 version 3.2.0 (C++/Java/Python/PHP/Ruby/Objective-C/C#/JavaScript/Lite)
   General
   * Added protoc version number to protoc plugin protocol. It can be used by
diff --git a/Protobuf.podspec b/Protobuf.podspec
index 0db70650ef..649f3ae3e1 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.2.0'
+  s.version  = '3.3.0'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/configure.ac b/configure.ac
index 531e25fbc8..82b221e84c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@ AC_PREREQ(2.59)
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.2.0],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.3.0],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 0b9cbcf423..182309bf13 100644
--- a/csharp/Google.Protobuf.Tools.nuspec
+++ b/csharp/Google.Protobuf.Tools.nuspec
@@ -5,7 +5,7 @@
     <title>Google Protocol Buffers tools</title>
     <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
     <description>See project site for more info.</description>
-    <version>3.2.0</version>
+    <version>3.3.0</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/google/protobuf/blob/master/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/project.json b/csharp/src/Google.Protobuf/project.json
index 961e037e18..f437623895 100644
--- a/csharp/src/Google.Protobuf/project.json
+++ b/csharp/src/Google.Protobuf/project.json
@@ -1,5 +1,5 @@
 {
-  "version": "3.2.0",
+  "version": "3.3.0",
   "title": "Google Protocol Buffers",
   "description": "See project site for more info.",
   "authors": [ "Google Inc." ],
diff --git a/js/package.json b/js/package.json
index dd6373de0d..14f54b8bfd 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.2.0",
+  "version": "3.3.0",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index 28a2511926..a06c99982a 100644
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@@ -10,7 +10,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protoc</artifactId>
-  <version>3.2.0</version>
+  <version>3.3.0</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index 7fd9e5a458..0375d72d0d 100755
--- a/python/google/protobuf/__init__.py
+++ b/python/google/protobuf/__init__.py
@@ -30,7 +30,7 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '3.2.0'
+__version__ = '3.3.0'
 
 if __name__ != '__main__':
   try:
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index 1e30ae4d7d..836b1dd282 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = "google-protobuf"
-  s.version     = "3.2.0.1"
+  s.version     = "3.3.0"
   s.licenses    = ["BSD-3-Clause"]
   s.summary     = "Protocol Buffers"
   s.description = "Protocol Buffers are Google's data interchange format."
diff --git a/src/Makefile.am b/src/Makefile.am
index 445474a0a1..bfb875acf4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -184,7 +184,7 @@ nobase_include_HEADERS =                                         \
 lib_LTLIBRARIES = libprotobuf-lite.la libprotobuf.la libprotoc.la
 
 libprotobuf_lite_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_lite_la_LDFLAGS = -version-info 12:0:0 -export-dynamic -no-undefined
+libprotobuf_lite_la_LDFLAGS = -version-info 13:0:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotobuf_lite_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotobuf-lite.map
 EXTRA_libprotobuf_lite_la_DEPENDENCIES = libprotobuf-lite.map
@@ -229,7 +229,7 @@ libprotobuf_lite_la_SOURCES =                                  \
   google/protobuf/io/zero_copy_stream_impl_lite.cc
 
 libprotobuf_la_LIBADD = $(PTHREAD_LIBS)
-libprotobuf_la_LDFLAGS = -version-info 12:0:0 -export-dynamic -no-undefined
+libprotobuf_la_LDFLAGS = -version-info 13:0:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotobuf_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotobuf.map
 EXTRA_libprotobuf_la_DEPENDENCIES = libprotobuf.map
@@ -318,7 +318,7 @@ libprotobuf_la_SOURCES =                                       \
 nodist_libprotobuf_la_SOURCES = $(nodist_libprotobuf_lite_la_SOURCES)
 
 libprotoc_la_LIBADD = $(PTHREAD_LIBS) libprotobuf.la
-libprotoc_la_LDFLAGS = -version-info 12:0:0 -export-dynamic -no-undefined
+libprotoc_la_LDFLAGS = -version-info 13:0:0 -export-dynamic -no-undefined
 if HAVE_LD_VERSION_SCRIPT
 libprotoc_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libprotoc.map
 EXTRA_libprotoc_la_DEPENDENCIES = libprotoc.map
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index d261149803..35fdf96b73 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -96,27 +96,27 @@ namespace internal {
 
 // The current version, represented as a single integer to make comparison
 // easier:  major * 10^6 + minor * 10^3 + micro
-#define GOOGLE_PROTOBUF_VERSION 3002000
+#define GOOGLE_PROTOBUF_VERSION 3003000
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
 #define GOOGLE_PROTOBUF_VERSION_SUFFIX ""
 
 // The minimum library version which works with the current version of the
 // headers.
-#define GOOGLE_PROTOBUF_MIN_LIBRARY_VERSION 3002000
+#define GOOGLE_PROTOBUF_MIN_LIBRARY_VERSION 3003000
 
 // The minimum header version which works with the current version of
 // the library.  This constant should only be used by protoc's C++ code
 // generator.
-static const int kMinHeaderVersionForLibrary = 3002000;
+static const int kMinHeaderVersionForLibrary = 3003000;
 
 // The minimum protoc version which works with the current version of the
 // headers.
-#define GOOGLE_PROTOBUF_MIN_PROTOC_VERSION 3002000
+#define GOOGLE_PROTOBUF_MIN_PROTOC_VERSION 3003000
 
 // The minimum header version which works with the current version of
 // protoc.  This constant should only be used in VerifyVersion().
-static const int kMinHeaderVersionForProtoc = 3002000;
+static const int kMinHeaderVersionForProtoc = 3003000;
 
 // Verifies that the headers and libraries are compatible.  Use the macro
 // below to call this.