diff --git a/.circleci/config.yml b/.circleci/config.yml
deleted file mode 100644
index b7d5e1d1..00000000
--- a/.circleci/config.yml
+++ /dev/null
@@ -1,26 +0,0 @@
-version: 2
-machine: true
-jobs:
-  build:
-    machine:
-      image: ubuntu-2004:202010-01
-    working_directory: ~/circleci-java
-    steps:
-      - run:
-          name: Install OpenJDK 11
-          command: |
-            sudo apt-get update && sudo apt-get install -y openjdk-11-jdk
-            sudo update-java-alternatives --jre-headless --jre --set java-1.11.0-openjdk-amd64
-            java -version
-      - checkout
-      - restore_cache:
-          key: maven-dependencies-{{ checksum "pom.xml" }}
-      - run: ./integration_test_suite/pull-smoke-test-docker-images.sh
-      - run: ./mvnw clean install
-      - run: ./mvnw javadoc:jar
-      - save_cache:
-          paths:
-            - ~/.m2
-          key: maven-dependencies-{{ checksum "pom.xml" }}
-orbs:
-  prometheus: prometheus/prometheus@0.16.0
diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 4ecdb464..fd81081d 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -14,10 +14,10 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          java-version: 17
+          java-version: 21 
           distribution: temurin
           cache: 'maven'
       - name: Run the Maven verify phase
         run: |
           ./mvnw --batch-mode clean install
-          ./mvnw javadoc:jar
\ No newline at end of file
+          ./mvnw javadoc:jar
diff --git a/.github/workflows/label-issues.yml b/.github/workflows/label-issues.yaml
similarity index 100%
rename from .github/workflows/label-issues.yml
rename to .github/workflows/label-issues.yaml
diff --git a/README.md b/README.md
index 346ef323..8cb2b4e2 100644
--- a/README.md
+++ b/README.md
@@ -1,22 +1,16 @@
-[![Build Status](https://circleci.com/gh/prometheus/jmx_exporter.svg?style=svg)](https://circleci.com/gh/prometheus/jmx_exporter)
-
 # JMX Exporter
 
-JMX to Prometheus exporter:
-
-A collector that can configurable scrape and expose MBeans of a JMX target.
+[![Build Status](https://github.com/prometheus/jmx_exporter/actions/workflows/build.yaml/badge.svg)](https://github.com/prometheus/jmx_exporter/actions/workflows/build.yaml)
 
-This exporter is intended to be run as a Java Agent, exposing either
-an HTTP endpoint or pushing Open Telemetry metrics of the local JVM.
+JMX to Prometheus exporter: a collector that can configurable scrape and
+expose MBeans of a JMX target.
 
-It can be also run as a standalone server and scrape remote JMX targets, but this has various
+This exporter is intended to be run as a Java Agent, exposing a HTTP server
+and serving metrics of the local JVM. It can be also run as a standalone
+HTTP server and scrape remote JMX targets, but this has various
 disadvantages, such as being harder to configure and being unable to expose
 process metrics (e.g., memory and CPU usage).
 
-In particular all the `jvm_*` metrics like `jvm_classes_loaded_total`, `jvm_threads_current`,
-`jvm_threads_daemon` and `jvm_memory_bytes_used` won't be available when
-using the standalone server.
-
 **Running the exporter as a Java agent is strongly encouraged.**
 
 # Documentation