diff --git a/babel/pom.xml b/babel/pom.xml
index e27b2e35ba00..b184f2dd51b6 100644
--- a/babel/pom.xml
+++ b/babel/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-babel</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Babel</name>
   <description>Calcite Babel</description>
 
diff --git a/cassandra/pom.xml b/cassandra/pom.xml
index ffa60aa5d2da..b075e0a02690 100644
--- a/cassandra/pom.xml
+++ b/cassandra/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-cassandra</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Cassandra</name>
   <description>Cassandra adapter for Calcite</description>
 
diff --git a/core/pom.xml b/core/pom.xml
index 63929734556b..fd34d5659dcf 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-core</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Core</name>
   <description>Core Calcite APIs and engine.</description>
 
diff --git a/druid/pom.xml b/druid/pom.xml
index 450f82d4db87..aa29109a9ca2 100644
--- a/druid/pom.xml
+++ b/druid/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-druid</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Druid</name>
   <description>Druid adapter for Calcite</description>
 
diff --git a/elasticsearch/pom.xml b/elasticsearch/pom.xml
index 6425d7b90783..a747b170afbd 100644
--- a/elasticsearch/pom.xml
+++ b/elasticsearch/pom.xml
@@ -21,12 +21,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-elasticsearch</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Elasticsearch</name>
   <description>Elasticsearch adapter for Calcite</description>
 
diff --git a/example/csv/pom.xml b/example/csv/pom.xml
index 663ab80464f7..0f7b79b0803b 100644
--- a/example/csv/pom.xml
+++ b/example/csv/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite-example</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-example-csv</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Example CSV</name>
   <description>An example Calcite provider that reads CSV files</description>
 
diff --git a/example/function/pom.xml b/example/function/pom.xml
index f3751dce0fd5..db6b13447bcb 100644
--- a/example/function/pom.xml
+++ b/example/function/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite-example</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-example-function</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Example Function</name>
   <description>Examples of user-defined Calcite functions</description>
 
diff --git a/example/pom.xml b/example/pom.xml
index fea1e6cac493..3bc039095c43 100644
--- a/example/pom.xml
+++ b/example/pom.xml
@@ -20,13 +20,13 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <!-- The basics. -->
   <artifactId>calcite-example</artifactId>
   <packaging>pom</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Examples</name>
   <description>Calcite examples</description>
 
diff --git a/file/pom.xml b/file/pom.xml
index 1c723b5bf744..be6341658070 100644
--- a/file/pom.xml
+++ b/file/pom.xml
@@ -19,13 +19,13 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <!-- The basics. -->
   <artifactId>calcite-file</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite File</name>
   <description>Calcite provider that reads files and URIs</description>
 
diff --git a/geode/pom.xml b/geode/pom.xml
index b9e4f9749623..20580bcbaab8 100644
--- a/geode/pom.xml
+++ b/geode/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-geode</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Geode</name>
   <description>Geode adapter for Calcite</description>
 
diff --git a/kafka/pom.xml b/kafka/pom.xml
index 153e2275de34..9437bbeba671 100644
--- a/kafka/pom.xml
+++ b/kafka/pom.xml
@@ -20,7 +20,7 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <!-- The basics. -->
diff --git a/linq4j/pom.xml b/linq4j/pom.xml
index 1c809aafb330..875766f45d62 100644
--- a/linq4j/pom.xml
+++ b/linq4j/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-linq4j</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Linq4j</name>
   <description>Calcite APIs for LINQ (Language-Integrated Query) in Java</description>
 
diff --git a/mongodb/pom.xml b/mongodb/pom.xml
index 8047ef46ae0b..0693db41bcd2 100644
--- a/mongodb/pom.xml
+++ b/mongodb/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-mongodb</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite MongoDB</name>
   <description>MongoDB adapter for Calcite</description>
 
diff --git a/pig/pom.xml b/pig/pom.xml
index de69253495fd..5337d0ff30d9 100644
--- a/pig/pom.xml
+++ b/pig/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-pig</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Pig</name>
   <description>Pig adapter for Calcite</description>
 
diff --git a/piglet/pom.xml b/piglet/pom.xml
index 20ab46db959a..3556abbf21eb 100644
--- a/piglet/pom.xml
+++ b/piglet/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-piglet</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Piglet</name>
   <description>Pig-like language built on top of Calcite algebra</description>
 
diff --git a/plus/pom.xml b/plus/pom.xml
index acbebe8942f1..149907723975 100644
--- a/plus/pom.xml
+++ b/plus/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-plus</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Plus</name>
   <description>Miscellaneous extras for Calcite</description>
 
diff --git a/pom.xml b/pom.xml
index 4060b0613721..a1d70d14eafd 100644
--- a/pom.xml
+++ b/pom.xml
@@ -27,7 +27,7 @@ limitations under the License.
   <groupId>org.apache.calcite</groupId>
   <artifactId>calcite</artifactId>
   <packaging>pom</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
 
   <!-- More project information. -->
   <name>Calcite</name>
@@ -169,7 +169,7 @@ limitations under the License.
     <connection>scm:git:https://gitbox.apache.org/repos/asf/calcite.git</connection>
     <developerConnection>scm:git:https://gitbox.apache.org/repos/asf/calcite.git</developerConnection>
     <url>https://github.com/apache/calcite</url>
-    <tag>HEAD</tag>
+    <tag>calcite-1.21.0</tag>
   </scm>
 
   <modules>
diff --git a/server/pom.xml b/server/pom.xml
index 356bc7c20e93..551d1c76a183 100644
--- a/server/pom.xml
+++ b/server/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-server</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Server</name>
   <description>Calcite Server</description>
 
diff --git a/spark/pom.xml b/spark/pom.xml
index 2defe94edeaa..6cef924ff5d8 100644
--- a/spark/pom.xml
+++ b/spark/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-spark</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Spark</name>
 
   <properties>
diff --git a/splunk/pom.xml b/splunk/pom.xml
index 35486e73b26f..e82cf94e4887 100644
--- a/splunk/pom.xml
+++ b/splunk/pom.xml
@@ -20,12 +20,12 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <artifactId>calcite-splunk</artifactId>
   <packaging>jar</packaging>
-  <version>1.21.0-SNAPSHOT</version>
+  <version>1.21.0</version>
   <name>Calcite Splunk</name>
   <description>Splunk adapter for Calcite; also a JDBC driver for Splunk</description>
 
diff --git a/ubenchmark/pom.xml b/ubenchmark/pom.xml
index 14c4838d9545..215a7af4fc80 100644
--- a/ubenchmark/pom.xml
+++ b/ubenchmark/pom.xml
@@ -20,7 +20,7 @@ limitations under the License.
   <parent>
     <groupId>org.apache.calcite</groupId>
     <artifactId>calcite</artifactId>
-    <version>1.21.0-SNAPSHOT</version>
+    <version>1.21.0</version>
   </parent>
 
   <properties>