diff --git a/backend/CMakeLists.txt b/backend/CMakeLists.txt
index c1153a5..fe2bfbf 100644
--- a/backend/CMakeLists.txt
+++ b/backend/CMakeLists.txt
@@ -4,6 +4,7 @@
 
 find_package(CURL)
 find_package(PkgConfig REQUIRED)
+find_package(SQLite3)
 pkg_check_modules(deps REQUIRED IMPORTED_TARGET glib-2.0 gio-2.0 bzip2)
 
 add_library(backend)
@@ -15,6 +16,6 @@ target_sources(backend
 configure_file(config.h.in ${CMAKE_BINARY_DIR}/generated/config.h)
 include_directories(${CMAKE_BINARY_DIR}/generated/)
 
-target_link_libraries(backend PkgConfig::deps CURL::libcurl)
+target_link_libraries(backend PkgConfig::deps CURL::libcurl ${SQLite3_LIBRARIES})
 
 file(COPY metadata.db DESTINATION ${CMAKE_BINARY_DIR}/${CMAKE_INSTALL_LOCALSTATEDIR})
diff --git a/backend/job.cpp b/backend/job.cpp
index 9aaabc7..68a2090 100644
--- a/backend/job.cpp
+++ b/backend/job.cpp
@@ -15,6 +15,7 @@ module;
 #include <curl/curl.h>
 #include <glib/gstdio.h>
 #include <sqlite3.h>
+#include <forward_list>
 
 export module katja.job;
 
@@ -24,19 +25,18 @@ import katja.slackpkg;
 
 namespace katja
 {
-static GSList *repos = nullptr;
+static std::forward_list<std::unique_ptr<Pkgtools>> repos;
 
 void pk_backend_initialize(GKeyFile *conf)
 {
     char *path, **groups;
     int ret;
-    gushort i;
-    gsize groups_len;
+    std::uint8_t i;
+    std::size_t groups_len;
     GFile *conf_file;
     GFileInfo *file_info;
     GKeyFile *key_conf;
     GError *err = nullptr;
-    void *repo = nullptr;
     sqlite3 *db;
     sqlite3_stmt *stmt;
 
@@ -107,9 +107,9 @@ void pk_backend_initialize(GKeyFile *conf)
 
         if (g_key_file_has_key(key_conf, groups[i], "Priority", nullptr))
         {
-            repo = new Slackpkg(groups[i], mirror, i + 1, blacklist,
+            auto repo = std::make_unique<Slackpkg>(groups[i], mirror, i + 1, blacklist,
                     g_key_file_get_string_list(key_conf, groups[i], "Priority", nullptr, nullptr));
-            repos = g_slist_append(repos, repo);
+            repos.emplace_front(std::move(repo));
         }
         g_free(mirror);
         g_free(blacklist);
@@ -123,12 +123,7 @@ void pk_backend_destroy()
 {
     g_debug("backend: destroy");
 
-    for (GSList *l = repos; l; l = g_slist_next(l))
-    {
-        delete static_cast<Pkgtools *>(l->data);
-    }
-
-    g_slist_free(repos);
+    repos.clear();
     curl_global_cleanup();
 }
 
@@ -257,7 +252,7 @@ void pk_backend_get_details(JobData *job_data, char **package_ids)
 {
     char *homepage = nullptr;
     char** tokens;
-    gsize i;
+    std::size_t i;
     GString *desc;
     GRegex *expr;
     GMatchInfo *match_info;
@@ -392,10 +387,10 @@ void pk_backend_download_packages(JobData *job_data, char **package_ids, const c
         sqlite3_bind_text(stmt, 4, tokens[3], -1, SQLITE_TRANSIENT);
         if (sqlite3_step(stmt) == SQLITE_ROW)
         {
-            GSList *repo;
-            if ((repo = g_slist_find_custom(repos, tokens[3], cmp_repo)))
+            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3]);
+            if (repo != std::end(repos))
             {
-                static_cast<Pkgtools *>(repo->data)->download(job_data, directory, tokens[0]);
+                (*repo)->download(job_data, directory, tokens[0]);
                 path = g_build_filename(directory, (char *) sqlite3_column_text(stmt, 1), nullptr);
                 to_strv[0] = path;
                 job_data->files(to_strv);
@@ -487,16 +482,13 @@ void pk_backend_install_packages(JobData *job_data, char **package_ids)
         dest_dir_name = g_build_filename(LOCALSTATEDIR, "cache", "katja", "downloads", nullptr);
         for (l = install_list, i = 0; l; l = g_slist_next(l), i++)
         {
-            char **tokens;
-            GSList *repo;
-
             job_data->set_percentage(percent_step * i);
-            tokens = g_strsplit((char *)(l->data), ";", 4);
-            repo = g_slist_find_custom(repos, tokens[3], cmp_repo);
+            char **tokens = g_strsplit((char *)(l->data), ";", 4);
+            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3]);
 
-            if (repo)
+            if (repo != std::end(repos))
             {
-                static_cast<Pkgtools *>(repo->data)->download(job_data, dest_dir_name, tokens[0]);
+                (*repo)->download(job_data, dest_dir_name, tokens[0]);
             }
             g_strfreev(tokens);
         }
@@ -505,16 +497,13 @@ void pk_backend_install_packages(JobData *job_data, char **package_ids)
         /* Install the packages */
         for (l = install_list; l; l = g_slist_next(l), i++)
         {
-            char **tokens;
-            GSList *repo;
-
             job_data->set_percentage(percent_step * i);
-            tokens = g_strsplit((char *)(l->data), ";", 4);
-            repo = g_slist_find_custom(repos, tokens[3], cmp_repo);
+            char **tokens = g_strsplit((char *)(l->data), ";", 4);
+            auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3]);
 
-            if (repo)
+            if (repo != std::end(repos))
             {
-                static_cast<Pkgtools *>(repo->data)->install(job_data, tokens[0]);
+                (*repo)->install(job_data, tokens[0]);
             }
             g_strfreev(tokens);
         }
@@ -530,17 +519,15 @@ void pk_backend_remove_packages(JobData* job_data, char **package_ids)
 {
     char *cmd_line;
     unsigned i;
-    gdouble percent_step;
+    double percent_step;
     GError *err = nullptr;
  
     /* Add percent_step percents per removed package */
     percent_step = 100.0 / g_strv_length(package_ids);
     for (i = 0; package_ids[i]; i++)
     {
-        char **tokens;
-
         job_data->set_percentage(percent_step * i);
-        tokens = g_strsplit(package_ids[i], ";", 4);
+        char **tokens = g_strsplit(package_ids[i], ";", 4);
         cmd_line = g_strconcat("/sbin/removepkg ", tokens[0], nullptr);
 
         /* Pkgtools return always 0 */
@@ -611,7 +598,7 @@ void pk_backend_get_updates(JobData *job_data)
         /* If there are more packages with the same name, remember the one from the
          * repository with the lowest order. */
         if ((sqlite3_step(stmt) == SQLITE_ROW)
-         || g_slist_find_custom(repos, ((char *) sqlite3_column_text(stmt, 4)), cmp_repo))
+         || cmp_repo(std::begin(repos), std::end(repos), (const char *) sqlite3_column_text(stmt, 4)) != std::end(repos))
         {
 
             full_name = g_strdup((char *) sqlite3_column_text(stmt, 0));
@@ -656,11 +643,11 @@ void pk_backend_update_packages(JobData *job_data, char **package_ids)
     for (i = 0; package_ids[i]; i++)
     {
         char **tokens = g_strsplit(package_ids[i], ";", 4);
-        GSList *repo = g_slist_find_custom(repos, tokens[3], cmp_repo);
+        auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3]);
 
-        if (repo)
+        if (repo != std::end(repos))
         {
-            static_cast<Pkgtools *>(repo->data)->download(job_data, dest_dir_name, tokens[0]);
+            (*repo)->download(job_data, dest_dir_name, tokens[0]);
         }
         g_strfreev(tokens);
     }
@@ -670,11 +657,11 @@ void pk_backend_update_packages(JobData *job_data, char **package_ids)
     for (i = 0; package_ids[i]; i++)
     {
         char **tokens = g_strsplit(package_ids[i], ";", 4);
-        GSList *repo = g_slist_find_custom(repos, tokens[3], cmp_repo);
+        auto repo = cmp_repo(std::begin(repos), std::end(repos), tokens[3]);
 
-        if (repo)
+        if (repo != std::end(repos))
         {
-            static_cast<Pkgtools *>(repo->data)->install(job_data, tokens[0]);
+            (*repo)->install(job_data, tokens[0]);
         }
         g_strfreev(tokens);
     }
@@ -684,7 +671,7 @@ void pk_backend_refresh_cache(JobData *job_data, bool force)
 {
     char *tmp_dir_name, *db_err, *path = nullptr;
     int ret;
-    GSList *file_list = nullptr;
+    std::forward_list<katja::cache_entry> file_list;
     GFile *db_file = nullptr;
     GFileInfo *file_info = nullptr;
     GError *err = nullptr;
@@ -737,24 +724,21 @@ void pk_backend_refresh_cache(JobData *job_data, bool force)
     }
 
     // Get list of files that should be downloaded.
-    for (GSList *l = repos; l; l = g_slist_next(l))
+    for (auto& l : repos)
     {
-        file_list = g_slist_concat(file_list,
-                static_cast<Pkgtools *>(l->data)->collect_cache_info(tmp_dir_name));
+        file_list.prepend_range(l->collect_cache_info(tmp_dir_name));
     }
 
     /* Download repository */
-    for (GSList *l = file_list; l; l = g_slist_next(l))
+    for (auto& l : file_list)
     {
-        get_file(&job_data->curl, static_cast<char **>(l->data)[0],
-                static_cast<char **>(l->data)[1]);
+        get_file(&job_data->curl, l.first.c_str(), l.second.native().c_str());
     }
-    g_slist_free_full(file_list, (GDestroyNotify) g_strfreev);
 
     /* Refresh cache */
-    for (GSList *l = repos; l; l = g_slist_next(l))
+    for (auto& l : repos)
     {
-        static_cast<Pkgtools *>(l->data)->generate_cache(job_data, tmp_dir_name);
+        l->generate_cache(job_data, tmp_dir_name);
     }
 
 out:
diff --git a/backend/pkgtools.cpp b/backend/pkgtools.cpp
index 58a752f..80dc4d8 100644
--- a/backend/pkgtools.cpp
+++ b/backend/pkgtools.cpp
@@ -12,6 +12,8 @@ module;
 #include <glib-object.h>
 #include <string>
 #include <regex>
+#include <forward_list>
+#include <filesystem>
 
 export module katja.pkgtools;
 
@@ -19,6 +21,8 @@ import katja.utils;
 
 export namespace katja
 {
+using cache_entry = std::pair<std::string, std::filesystem::path>;
+
 class Pkgtools
 {
 public:
@@ -160,7 +164,7 @@ public:
         sqlite3_finalize(statement);
     }
 
-    virtual GSList *collect_cache_info (const char *tmpl) noexcept = 0;
+    virtual std::forward_list<cache_entry> collect_cache_info(const char *tmpl) noexcept = 0;
     virtual void generate_cache(JobData *job_data, const char *tmpl) noexcept = 0;
 
 protected:
@@ -170,10 +174,11 @@ protected:
 /**
  * katja::cmp_repo:
  **/
-int cmp_repo(const void *a, const void *b)
+template<class InputIt>
+InputIt cmp_repo(InputIt first, InputIt last, const char *a)
 {
-    auto repo = static_cast<const Pkgtools *> (a);
-
-    return g_strcmp0(repo->name.c_str(), (char *) b);
+    return std::find_if(first, last, [a](std::unique_ptr<Pkgtools>& repo) {
+        return repo->name == a;
+    });
 }
 }
diff --git a/backend/slackpkg.cpp b/backend/slackpkg.cpp
index fd7ea22..d546b5e 100644
--- a/backend/slackpkg.cpp
+++ b/backend/slackpkg.cpp
@@ -16,6 +16,8 @@ module;
 #include <string>
 #include <regex>
 #include <vector>
+#include <forward_list>
+#include <filesystem>
 
 export module katja.slackpkg;
 
@@ -47,30 +49,12 @@ public:
         {
             this->blacklist = std::regex(blacklist);
         }
-        for (char **cur_priority = priority; *cur_priority; cur_priority++)
+        if (priority != nullptr)
         {
-            this->priority.emplace_back(*cur_priority);
-        }
-        // Initialize category map
-        if (cat_map == nullptr)
-        {
-            cat_map = g_hash_table_new(g_str_hash, g_str_equal);
-            g_hash_table_insert(cat_map, (void *) "a", (void *) "system");
-            g_hash_table_insert(cat_map, (void *) "ap", (void *) "admin-tools");
-            g_hash_table_insert(cat_map, (void *) "d", (void *) "programming");
-            g_hash_table_insert(cat_map, (void *) "e", (void *) "programming");
-            g_hash_table_insert(cat_map, (void *) "f", (void *) "documentation");
-            g_hash_table_insert(cat_map, (void *) "k", (void *) "system");
-            g_hash_table_insert(cat_map, (void *) "kde", (void *) "desktop-kde");
-            g_hash_table_insert(cat_map, (void *) "kdei", (void *) "localization");
-            g_hash_table_insert(cat_map, (void *) "l", (void *) "system");
-            g_hash_table_insert(cat_map, (void *) "n", (void *) "network");
-            g_hash_table_insert(cat_map, (void *) "t", (void *) "publishing");
-            g_hash_table_insert(cat_map, (void *) "tcl", (void *) "system");
-            g_hash_table_insert(cat_map, (void *) "x", (void *) "desktop-other");
-            g_hash_table_insert(cat_map, (void *) "xap", (void *) "accessories");
-            g_hash_table_insert(cat_map, (void *) "xfce", (void *) "desktop-xfce");
-            g_hash_table_insert(cat_map, (void *) "y", (void *) "games");
+            for (char **cur_priority = priority; *cur_priority; cur_priority++)
+            {
+                this->priority.emplace_back(*cur_priority);
+            }
         }
     }
 
@@ -83,11 +67,11 @@ public:
      *
      * Returns: List of files needed for building the cache.
      **/
-    GSList *collect_cache_info(const char *tmpl) noexcept
+    std::forward_list<cache_entry> collect_cache_info(const char *tmpl) noexcept
     {
         CURL *curl = nullptr;
-        char **source_dest;
-        GSList *file_list = nullptr;
+        cache_entry source_dest;
+        std::forward_list<cache_entry> file_list;
         GFile *tmp_dir, *repo_tmp_dir;
 
         /* Create the temporary directory for the repository */
@@ -98,34 +82,25 @@ public:
         /* Download PACKAGES.TXT. These files are most important, break if some of them couldn't be found */
         for (const std::string& current_priority : this->priority)
         {
-            source_dest = static_cast<char **> (g_malloc_n(3, sizeof(char *)));
-            source_dest[0] = g_strconcat(this->mirror.c_str(), current_priority.c_str(), "/PACKAGES.TXT", nullptr);
-            source_dest[1] = g_build_filename(tmpl, this->name.c_str(), "PACKAGES.TXT", nullptr);
-            source_dest[2] = nullptr;
+            source_dest.first = this->mirror + current_priority + "/PACKAGES.TXT";
+            source_dest.second = std::filesystem::path(tmpl) / this->name / "PACKAGES.TXT";
 
-            if (get_file(&curl, source_dest[0], nullptr) == CURLE_OK)
+            if (get_file(&curl, source_dest.first.c_str(), nullptr) == CURLE_OK)
             {
-                file_list = g_slist_prepend(file_list, source_dest);
+                file_list.emplace_front(std::move(source_dest));
             }
             else
             {
-                g_strfreev(source_dest);
-                g_slist_free_full(file_list, (GDestroyNotify)g_strfreev);
                 goto out;
             }
 
             /* Download file lists if available */
-            source_dest = static_cast<char **> (g_malloc_n(3, sizeof(char *)));
-            source_dest[0] = g_strconcat(this->mirror.c_str(), current_priority.c_str(), "/MANIFEST.bz2", nullptr);
-            source_dest[1] = g_strconcat(tmpl, "/", this->name.c_str(), "/", *current_priority.c_str(), "-MANIFEST.bz2", nullptr);
-            source_dest[2] = nullptr;
-            if (get_file(&curl, source_dest[0], nullptr) == CURLE_OK)
+            source_dest.first = this->mirror + current_priority + "/MANIFEST.bz2";
+            source_dest.second = std::filesystem::path(tmpl) / this->name / (current_priority + "-MANIFEST.bz2");
+
+            if (get_file(&curl, source_dest.first.c_str(), nullptr) == CURLE_OK)
             {
-                file_list = g_slist_prepend(file_list, source_dest);
-            }
-            else
-            {
-                g_strfreev(source_dest);
+                file_list.emplace_front(std::move(source_dest));
             }
         }
     out:
@@ -154,7 +129,7 @@ public:
         char **pkg_tokens = nullptr;
         char *query = nullptr, *filename = nullptr, *location = nullptr, *summary = nullptr, *line, *packages_txt;
         unsigned pkg_compressed = 0, pkg_uncompressed = 0;
-        gushort pkg_name_len;
+        std::uint8_t pkg_name_len;
         GString *desc;
         GFile *list_file;
         GFileInputStream *fin = nullptr;
@@ -279,12 +254,9 @@ public:
                 {
                     /* Get the package group based on its location */
                     const char *cat = g_strrstr(location, "/");
-                    if (cat) /* Else cat = nullptr */
-                    {
-                        cat = static_cast<const char *>(g_hash_table_lookup(cat_map, cat + 1));
-                    }
                     if (cat)
                     {
+                        ++cat;
                         statement = insert_statement;
                         sqlite3_bind_text(insert_statement, 12, cat, -1, SQLITE_TRANSIENT);
                     }
@@ -349,7 +321,6 @@ public:
     }
 
 private:
-    static inline GHashTable *cat_map{ nullptr };
     static const std::size_t max_buf_size = 8192;
     std::vector<std::string> priority;
 
diff --git a/backend/utils.cpp b/backend/utils.cpp
index 086fa42..19d0b39 100644
--- a/backend/utils.cpp
+++ b/backend/utils.cpp
@@ -52,9 +52,9 @@ struct JobData
  *
  * Returns: CURLE_OK (zero) on success, non-zero otherwise.
  **/
-CURLcode get_file(CURL **curl, char *source_url, char *dest)
+CURLcode get_file(CURL **curl, const char *source_url, const char *dest)
 {
-    char *dest_dir_name;
+    const char *dest_dir_name;
     FILE *fout = nullptr;
     CURLcode ret;
     glong response_code;
@@ -85,7 +85,7 @@ CURLcode get_file(CURL **curl, char *source_url, char *dest)
         {
             dest_dir_name = dest;
             dest = g_strconcat(dest_dir_name, g_strrstr(source_url, "/"), nullptr);
-            g_free(dest_dir_name);
+            g_free(const_cast<char *>(dest_dir_name));
         }
         if ((fout = fopen(dest, "ab")) == nullptr)
         {
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 3555ece..d6f74f4 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -13,7 +13,7 @@ foreach(test_source ${KATJA_TEST_SOURCES})
 	add_executable(${tester} ${test_source})
 
 	target_compile_definitions(${tester} PRIVATE "BOOST_TEST_DYN_LINK=1")
-	target_link_libraries(${tester} PRIVATE katja Boost::unit_test_framework)
+	target_link_libraries(${tester} PRIVATE katja backend Boost::unit_test_framework)
 
 	add_test(NAME ${test_name} COMMAND ${tester})
 endforeach()
diff --git a/backend/tests/slackpkg-test.cc b/tests/slackpkg.cpp
similarity index 65%
rename from backend/tests/slackpkg-test.cc
rename to tests/slackpkg.cpp
index 89406af..9a47765 100644
--- a/backend/tests/slackpkg-test.cc
+++ b/tests/slackpkg.cpp
@@ -10,11 +10,11 @@ import katja.slackpkg;
 
 BOOST_AUTO_TEST_CASE(slack_test_slackpkg_construct)
 {
-    auto slackpkg = new Slackpkg("some", "mirror", 1, nullptr, nullptr);
+    auto slackpkg = new katja::Slackpkg("some", "mirror", 1, nullptr, nullptr);
 
-    BOOST_TEST(strcmp(slackpkg->get_name(), "some") == 0);
-    BOOST_TEST(strcmp(slackpkg->get_mirror(), "mirror") == 0);
-    BOOST_TEST(slackpkg->get_order() == 1);
+    BOOST_TEST(slackpkg->name == "some");
+    BOOST_TEST(slackpkg->mirror == "mirror");
+    BOOST_TEST(slackpkg->order == 1);
     BOOST_TEST(!slackpkg->is_blacklisted("pattern"));
 
     delete slackpkg;