Improved Eclipse support (as much as possible, since Eclipse doesn't understand that sourcesets should have different dependencies).
diff --git a/build.gradle.kts b/build.gradle.kts
index 6391c08..bd6ae0f 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -26,6 +26,7 @@
     `maven-publish`
     signing
     id("biz.aQute.bnd.builder") version "6.1.0"
+    id("eclipse")
 }
 
 group = "org.freemarker"
@@ -460,6 +461,19 @@
 registerDistRatTask("ratDistBin", file("src/dist/bin/rat-excludes"), distBin)
 registerDistRatTask("ratDistSrc", file("rat-excludes"), distSrc)
 
+eclipse {
+    classpath {
+        // Eclipse sees only a single classpath,
+        // so make a best effort for a combined classpath.
+        plusConfigurations = listOf(
+            configurations["combinedClasspath"],
+            configurations["core16CompileClasspath"],
+            configurations["testUtilsCompileClasspath"],
+            configurations["jsp21TestCompileClasspath"]
+        )
+    }
+}
+
 // Choose the Jetty version very carefully, as it should implement the same Servlet API, JSP API, and EL API
 // what we declare below, because the same classes will come from Jetty as well. For example, Jetty depends
 // on org.mortbay.jasper:apache-el, which contains the javax.el classes, along with non-javax.el classes, so you