diff --git a/core/config.go b/core/config.go
index 6c4f9574..0ee6921f 100644
--- a/core/config.go
+++ b/core/config.go
@@ -7,6 +7,7 @@ import (
 	"github.com/safing/portbase/log"
 )
 
+// Configuration Keys
 var (
 	CfgDevModeKey  = "core/devMode"
 	defaultDevMode bool
diff --git a/core/core.go b/core/core.go
index 7b3b4532..f15a2709 100644
--- a/core/core.go
+++ b/core/core.go
@@ -3,9 +3,14 @@ package core
 import (
 	"fmt"
 
+	"github.com/safing/portbase/modules"
 	"github.com/safing/portbase/modules/subsystems"
 
-	"github.com/safing/portbase/modules"
+	// module dependencies
+	_ "github.com/safing/portbase/rng"
+	_ "github.com/safing/portmaster/status"
+	_ "github.com/safing/portmaster/ui"
+	_ "github.com/safing/portmaster/updates"
 )
 
 var (
@@ -13,7 +18,9 @@ var (
 )
 
 func init() {
-	module = modules.Register("core", nil, start, nil, "database", "config", "api", "random", "notifications", "subsystems", "ui", "updates", "status")
+	modules.Register("base", nil, registerDatabases, nil, "database", "config", "random")
+
+	module = modules.Register("core", nil, start, nil, "base", "subsystems", "status", "updates", "api", "notifications", "ui")
 	subsystems.Register(
 		"core",
 		"Core",
@@ -29,5 +36,5 @@ func start() error {
 		return fmt.Errorf("failed to start plattform-specific components: %s", err)
 	}
 
-	return registerDatabases()
+	return nil
 }
diff --git a/core/databases.go b/core/databases.go
index 65612e8c..941aa97a 100644
--- a/core/databases.go
+++ b/core/databases.go
@@ -10,6 +10,7 @@ import (
 	_ "github.com/safing/portbase/database/storage/bbolt"
 )
 
+// Default Values (changeable for testing)
 var (
 	DefaultDatabaseStorageType = "bbolt"
 )
diff --git a/core/global.go b/core/global.go
index 13c6cfa9..d76bbaa5 100644
--- a/core/global.go
+++ b/core/global.go
@@ -12,7 +12,10 @@ import (
 	"github.com/safing/portbase/notifications"
 )
 
+// Default Values (changeable for testing)
 var (
+	DefaultAPIListenAddress = "127.0.0.1:817"
+
 	dataDir     string
 	databaseDir string
 )
@@ -53,7 +56,7 @@ func globalPrep() error {
 	}
 
 	// set api listen address
-	api.SetDefaultAPIListenAddress("127.0.0.1:817")
+	api.SetDefaultAPIListenAddress(DefaultAPIListenAddress)
 
 	// set notification persistence
 	notifications.SetPersistenceBasePath("core:notifications")
diff --git a/core/pmtesting/testing.go b/core/pmtesting/testing.go
index fc5005b2..04779939 100644
--- a/core/pmtesting/testing.go
+++ b/core/pmtesting/testing.go
@@ -1,6 +1,18 @@
-// package coretest provides a simple unit test setup routine.
+// Package pmtesting provides a simple unit test setup routine.
 //
-// Just include `_ "github.com/safing/portmaster/core/pmtesting"`
+// Usage:
+//
+// 		package name
+//
+// 		import (
+// 			"testing"
+//
+// 			"github.com/safing/portmaster/core/pmtesting"
+// 		)
+//
+// 		func TestMain(m *testing.M) {
+// 			pmtesting.TestMain(m, module)
+// 		}
 //
 package pmtesting
 
@@ -29,10 +41,17 @@ func init() {
 	flag.BoolVar(&printStackOnExit, "print-stack-on-exit", false, "prints the stack before of shutting down")
 }
 
-func TestMain(m *testing.M) {
+// TestMain provides a simple unit test setup routine.
+func TestMain(m *testing.M, module *modules.Module) {
+	// enable module for testing
+	module.Enable()
+
 	// switch databases to memory only
 	core.DefaultDatabaseStorageType = "hashmap"
 
+	// switch API to high port
+	core.DefaultAPIListenAddress = "127.0.0.1:10817"
+
 	// set log level
 	log.SetLogLevel(log.TraceLevel)
 
@@ -40,19 +59,22 @@ func TestMain(m *testing.M) {
 	tmpDir := filepath.Join(os.TempDir(), "portmaster-testing")
 	// initialize data dir
 	err := dataroot.Initialize(tmpDir, 0755)
-	// start modules
-	if err == nil {
-		err = modules.Start()
-	}
-	// handle setup error
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "failed to setup test: %s\n", err)
-		printStack()
+		fmt.Fprintf(os.Stderr, "failed to initialize data root: %s\n", err)
 		os.Exit(1)
 	}
 
-	// run tests
-	exitCode := m.Run()
+	// start modules
+	var exitCode int
+	err = modules.Start()
+	if err != nil {
+		// starting failed
+		fmt.Fprintf(os.Stderr, "failed to setup test: %s\n", err)
+		exitCode = 1
+	} else {
+		// run tests
+		exitCode = m.Run()
+	}
 
 	// shutdown
 	_ = modules.Shutdown()
@@ -63,7 +85,14 @@ func TestMain(m *testing.M) {
 	printStack()
 
 	// clean up and exit
-	// keep! os.RemoveAll(tmpDir)
+
+	// Important: Do not remove tmpDir, as it is used as a cache for updates.
+	// remove config
+	_ = os.Remove(filepath.Join(tmpDir, "config.json"))
+	// remove databases
+	_ = os.Remove(filepath.Join(tmpDir, "databases.json"))
+	_ = os.RemoveAll(filepath.Join(tmpDir, "databases"))
+
 	os.Exit(exitCode)
 }
 
diff --git a/firewall/config.go b/firewall/config.go
index 62f505ef..721d1382 100644
--- a/firewall/config.go
+++ b/firewall/config.go
@@ -4,6 +4,7 @@ import (
 	"github.com/safing/portbase/config"
 )
 
+// Configuration Keys
 var (
 	CfgOptionEnableFilterKey = "filter/enable"
 
diff --git a/firewall/dialer.go b/firewall/dialer.go
index bf158b65..270b3f9f 100644
--- a/firewall/dialer.go
+++ b/firewall/dialer.go
@@ -4,13 +4,13 @@ import (
 	"fmt"
 	"net"
 
-	"github.com/safing/portmaster/network/environment"
+	"github.com/safing/portmaster/netenv"
 	"github.com/safing/portmaster/resolver"
 )
 
 func init() {
 	resolver.SetLocalAddrFactory(PermittedAddr)
-	environment.SetLocalAddrFactory(PermittedAddr)
+	netenv.SetLocalAddrFactory(PermittedAddr)
 }
 
 // PermittedAddr returns an already permitted local address for the given network for reliable connectivity.
diff --git a/firewall/firewall.go b/firewall/firewall.go
index dc6231a7..0b32a9a0 100644
--- a/firewall/firewall.go
+++ b/firewall/firewall.go
@@ -44,7 +44,7 @@ var (
 )
 
 func init() {
-	module = modules.Register("firewall", prep, start, stop, "core", "network", "resolver", "intel", "processes")
+	module = modules.Register("filter", prep, start, stop, "core", "network", "nameserver", "intel")
 	subsystems.Register(
 		"filter",
 		"Privacy Filter",
diff --git a/intel/geoip/module_test.go b/intel/geoip/module_test.go
index 1b32ad88..c1ae951b 100644
--- a/intel/geoip/module_test.go
+++ b/intel/geoip/module_test.go
@@ -7,5 +7,5 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	pmtesting.TestMain(m)
+	pmtesting.TestMain(m, module)
 }
diff --git a/intel/module.go b/intel/module.go
index 99169de3..ea4d013f 100644
--- a/intel/module.go
+++ b/intel/module.go
@@ -4,6 +4,11 @@ import (
 	"github.com/safing/portbase/modules"
 )
 
+var (
+	// Module of this package. Export needed for testing of the endpoints package.
+	Module *modules.Module
+)
+
 func init() {
-	modules.Register("intel", nil, nil, nil, "geoip")
+	Module = modules.Register("intel", nil, nil, nil, "geoip")
 }
diff --git a/nameserver/nameserver.go b/nameserver/nameserver.go
index ba7c6577..6c7a7601 100644
--- a/nameserver/nameserver.go
+++ b/nameserver/nameserver.go
@@ -11,8 +11,8 @@ import (
 	"github.com/safing/portbase/modules"
 	"github.com/safing/portmaster/detection/dga"
 	"github.com/safing/portmaster/firewall"
+	"github.com/safing/portmaster/netenv"
 	"github.com/safing/portmaster/network"
-	"github.com/safing/portmaster/network/environment"
 	"github.com/safing/portmaster/network/netutils"
 	"github.com/safing/portmaster/resolver"
 
@@ -30,7 +30,7 @@ var (
 )
 
 func init() {
-	module = modules.Register("nameserver", prep, start, stop, "core", "resolver", "network")
+	module = modules.Register("nameserver", prep, start, stop, "core", "resolver", "network", "netenv")
 	subsystems.Register(
 		"dns",
 		"Secure DNS",
@@ -108,9 +108,9 @@ func handleRequestAsMicroTask(w dns.ResponseWriter, query *dns.Msg) {
 	}
 }
 
-func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) error {
+func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) error { //nolint:gocognit // TODO
 	// return with server failure if offline
-	if environment.GetOnlineStatus() == environment.StatusOffline {
+	if netenv.GetOnlineStatus() == netenv.StatusOffline {
 		returnServerFailure(w, query)
 		return nil
 	}
diff --git a/nameserver/only/nameserver.go b/nameserver/only/nameserver.go
index 24920477..feaa5ca5 100644
--- a/nameserver/only/nameserver.go
+++ b/nameserver/only/nameserver.go
@@ -5,15 +5,13 @@ import (
 	"net"
 	"strings"
 
-	"github.com/safing/portmaster/network/environment"
-
-	"github.com/miekg/dns"
-
 	"github.com/safing/portbase/log"
 	"github.com/safing/portbase/modules"
-
-	"github.com/safing/portmaster/intel"
+	"github.com/safing/portmaster/netenv"
 	"github.com/safing/portmaster/network/netutils"
+	"github.com/safing/portmaster/resolver"
+
+	"github.com/miekg/dns"
 )
 
 var (
@@ -27,7 +25,7 @@ var (
 )
 
 func init() {
-	module = modules.Register("nameserver", initLocalhostRRs, start, stop, "core", "intel", "network")
+	module = modules.Register("nameserver", initLocalhostRRs, start, stop, "core", "resolver", "network", "netenv")
 }
 
 func initLocalhostRRs() error {
@@ -53,7 +51,7 @@ func start() error {
 		err := dnsServer.ListenAndServe()
 		if err != nil {
 			// check if we are shutting down
-			if module.ShutdownInProgress() {
+			if module.IsStopping() {
 				return nil
 			}
 		}
@@ -87,20 +85,20 @@ func handleRequestAsMicroTask(w dns.ResponseWriter, query *dns.Msg) {
 		return handleRequest(ctx, w, query)
 	})
 	if err != nil {
-		log.Warningf("intel: failed to handle dns request: %s", err)
+		log.Warningf("nameserver: failed to handle dns request: %s", err)
 	}
 }
 
 func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) error {
 	// return with server failure if offline
-	if environment.GetOnlineStatus() == environment.StatusOffline {
+	if netenv.GetOnlineStatus() == netenv.StatusOffline {
 		returnServerFailure(w, query)
 		return nil
 	}
 
 	// only process first question, that's how everyone does it.
 	question := query.Question[0]
-	q := &intel.Query{
+	q := &resolver.Query{
 		FQDN:  question.Name,
 		QType: dns.Type(question.Qtype),
 	}
@@ -157,7 +155,7 @@ func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) er
 	// TODO: if there are 3 request for the same domain/type in a row, delete all caches of that domain
 
 	// get intel and RRs
-	rrCache, err := intel.Resolve(ctx, q)
+	rrCache, err := resolver.Resolve(ctx, q)
 	if err != nil {
 		// TODO: analyze nxdomain requests, malware could be trying DGA-domains
 		tracer.Warningf("nameserver: request for %s%s: %s", q.FQDN, q.QType, err)
@@ -169,9 +167,9 @@ func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) er
 	for _, rr := range append(rrCache.Answer, rrCache.Extra...) {
 		switch v := rr.(type) {
 		case *dns.A:
-			ipInfo, err := intel.GetIPInfo(v.A.String())
+			ipInfo, err := resolver.GetIPInfo(v.A.String())
 			if err != nil {
-				ipInfo = &intel.IPInfo{
+				ipInfo = &resolver.IPInfo{
 					IP:      v.A.String(),
 					Domains: []string{q.FQDN},
 				}
@@ -183,9 +181,9 @@ func handleRequest(ctx context.Context, w dns.ResponseWriter, query *dns.Msg) er
 				}
 			}
 		case *dns.AAAA:
-			ipInfo, err := intel.GetIPInfo(v.AAAA.String())
+			ipInfo, err := resolver.GetIPInfo(v.AAAA.String())
 			if err != nil {
-				ipInfo = &intel.IPInfo{
+				ipInfo = &resolver.IPInfo{
 					IP:      v.AAAA.String(),
 					Domains: []string{q.FQDN},
 				}
diff --git a/pmctl/main.go b/pmctl/main.go
index 2c99fe2f..6cea5b6e 100644
--- a/pmctl/main.go
+++ b/pmctl/main.go
@@ -9,14 +9,12 @@ import (
 	"strings"
 	"syscall"
 
-	"github.com/safing/portbase/updater"
-
-	"github.com/safing/portmaster/core/structure"
-
-	"github.com/safing/portbase/utils"
-
+	"github.com/safing/portbase/dataroot"
 	"github.com/safing/portbase/info"
 	portlog "github.com/safing/portbase/log"
+	"github.com/safing/portbase/updater"
+	"github.com/safing/portbase/utils"
+
 	"github.com/spf13/cobra"
 )
 
@@ -158,15 +156,15 @@ func cmdSetup(cmd *cobra.Command, args []string) (err error) {
 
 		// remove redundant escape characters and quotes
 		dataDir = strings.Trim(dataDir, `\"`)
-		// initialize structure
-		err = structure.Initialize(dataDir, 0755)
+		// initialize dataroot
+		err = dataroot.Initialize(dataDir, 0755)
 		if err != nil {
 			return fmt.Errorf("failed to initialize data root: %s", err)
 		}
-		dataRoot = structure.Root()
+		dataRoot = dataroot.Root()
 
 		// initialize registry
-		err := registry.Initialize(structure.Root().ChildDir("updates", 0755))
+		err := registry.Initialize(dataRoot.ChildDir("updates", 0755))
 		if err != nil {
 			return err
 		}
@@ -187,7 +185,7 @@ func cmdSetup(cmd *cobra.Command, args []string) (err error) {
 	// logs and warning
 	if !showShortVersion && !showFullVersion && !strings.Contains(cmd.CommandPath(), " show ") {
 		// set up logs root
-		logsRoot = structure.NewRootDir("logs", 0777)
+		logsRoot = dataRoot.ChildDir("logs", 0777)
 		err = logsRoot.Ensure()
 		if err != nil {
 			return fmt.Errorf("failed to initialize logs root: %s", err)
diff --git a/process/config.go b/process/config.go
index 36722fe5..9329eddb 100644
--- a/process/config.go
+++ b/process/config.go
@@ -4,6 +4,7 @@ import (
 	"github.com/safing/portbase/config"
 )
 
+// Configuration Keys
 var (
 	CfgOptionEnableProcessDetectionKey = "core/enableProcessDetection"
 	enableProcessDetection             config.BoolOption
diff --git a/process/module_test.go b/process/module_test.go
new file mode 100644
index 00000000..fc33c7bd
--- /dev/null
+++ b/process/module_test.go
@@ -0,0 +1,11 @@
+package process
+
+import (
+	"testing"
+
+	"github.com/safing/portmaster/core/pmtesting"
+)
+
+func TestMain(m *testing.M) {
+	pmtesting.TestMain(m, module)
+}
diff --git a/profile/config.go b/profile/config.go
index db03a9d1..49f64160 100644
--- a/profile/config.go
+++ b/profile/config.go
@@ -4,6 +4,7 @@ import (
 	"github.com/safing/portbase/config"
 )
 
+// Configuration Keys
 var (
 	cfgStringOptions      = make(map[string]config.StringOption)
 	cfgStringArrayOptions = make(map[string]config.StringArrayOption)
diff --git a/profile/endpoints/endpoints_test.go b/profile/endpoints/endpoints_test.go
index 147e6bf4..0eb4e2e1 100644
--- a/profile/endpoints/endpoints_test.go
+++ b/profile/endpoints/endpoints_test.go
@@ -10,7 +10,7 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	pmtesting.TestMain(m)
+	pmtesting.TestMain(m, intel.Module)
 }
 
 func testEndpointMatch(t *testing.T, ep Endpoint, entity *intel.Entity, expectedResult EPResult) {
diff --git a/profile/find.go b/profile/find.go
index 51475bce..85ad5a7d 100644
--- a/profile/find.go
+++ b/profile/find.go
@@ -5,6 +5,7 @@ import (
 	"github.com/safing/portbase/log"
 )
 
+// FindOrCreateLocalProfileByPath returns an existing or new profile for the given application path.
 func FindOrCreateLocalProfileByPath(fullPath string) (profile *Profile, new bool, err error) {
 	// find local profile
 	it, err := profileDB.Query(
diff --git a/profile/fingerprint/fingerprint.go b/profile/fingerprint/fingerprint.go
index d049d42c..7d7d4bde 100644
--- a/profile/fingerprint/fingerprint.go
+++ b/profile/fingerprint/fingerprint.go
@@ -47,3 +47,41 @@ func (profile *Profile) AddFingerprint(fp *Fingerprint) {
 	profile.Fingerprints = append(profile.Fingerprints, fp)
 }
 */
+
+// TODO: matching
+/*
+//nolint:deadcode,unused // FIXME
+func matchProfile(p *Process, prof *profile.Profile) (score int) {
+	for _, fp := range prof.Fingerprints {
+		score += matchFingerprint(p, fp)
+	}
+	return
+}
+
+//nolint:deadcode,unused // FIXME
+func matchFingerprint(p *Process, fp *profile.Fingerprint) (score int) {
+	if !fp.MatchesOS() {
+		return 0
+	}
+
+	switch fp.Type {
+	case "full_path":
+		if p.Path == fp.Value {
+			return profile.GetFingerprintWeight(fp.Type)
+		}
+	case "partial_path":
+		// FIXME: if full_path matches, do not match partial paths
+		return profile.GetFingerprintWeight(fp.Type)
+	case "md5_sum", "sha1_sum", "sha256_sum":
+		// FIXME: one sum is enough, check sums in a grouped form, start with the best
+		sum, err := p.GetExecHash(fp.Type)
+		if err != nil {
+			log.Errorf("process: failed to get hash of executable: %s", err)
+		} else if sum == fp.Value {
+			return profile.GetFingerprintWeight(fp.Type)
+		}
+	}
+
+	return 0
+}
+*/
diff --git a/profile/module_test.go b/profile/module_test.go
new file mode 100644
index 00000000..55bd1876
--- /dev/null
+++ b/profile/module_test.go
@@ -0,0 +1,11 @@
+package profile
+
+import (
+	"testing"
+
+	"github.com/safing/portmaster/core/pmtesting"
+)
+
+func TestMain(m *testing.M) {
+	pmtesting.TestMain(m, module)
+}
diff --git a/status/module.go b/status/module.go
index f7ac9231..da3486e9 100644
--- a/status/module.go
+++ b/status/module.go
@@ -4,13 +4,10 @@ import (
 	"github.com/safing/portbase/database"
 	"github.com/safing/portbase/log"
 	"github.com/safing/portbase/modules"
-
-	// module dependencies
-	_ "github.com/safing/portmaster/core"
 )
 
 func init() {
-	modules.Register("status", nil, start, stop, "config", "database")
+	modules.Register("status", nil, start, stop, "base")
 }
 
 func start() error {
diff --git a/ui/serve.go b/ui/serve.go
index 96bb34b9..2dcd219d 100644
--- a/ui/serve.go
+++ b/ui/serve.go
@@ -115,8 +115,8 @@ func ServeFileFromBundle(w http.ResponseWriter, r *http.Request, bundleName stri
 		}
 	}
 
-	// set content security policy
-	// FIXME: this breaks the ui client
+	// TODO: Set content security policy
+	// For some reason, this breaks the ui client
 	// w.Header().Set("Content-Security-Policy", "default-src 'self'")
 
 	w.WriteHeader(http.StatusOK)
diff --git a/updates/main.go b/updates/main.go
index e7a550a7..31bc3065 100644
--- a/updates/main.go
+++ b/updates/main.go
@@ -29,7 +29,7 @@ var (
 )
 
 func init() {
-	module = modules.Register("updates", registerConfig, start, stop, "config", "database")
+	module = modules.Register("updates", registerConfig, start, stop, "base")
 	module.RegisterEvent(eventVersionUpdate)
 	module.RegisterEvent(eventResourceUpdate)
 }