diff --git a/README.md b/README.md
index b8c0e9f1..cdebf94c 100644
--- a/README.md
+++ b/README.md
@@ -20,8 +20,7 @@ development and thus somewhat experimental.
 
 ### Requirements
 
-The command-line interface requires python3.5 or higher. The analyzer
-requires a Java development kit (to provide the `jar` tool).
+The command-line interface requires python3.5 or higher.
 
 Build instructions for the CodeHawk Binary Analyzer are available
 [here](https://github.com/static-analysis-engineering/codehawk/tree/master/CodeHawk).
diff --git a/chb/app/AppAccess.py b/chb/app/AppAccess.py
index 9f93b535..dcdf46c8 100644
--- a/chb/app/AppAccess.py
+++ b/chb/app/AppAccess.py
@@ -103,7 +103,7 @@ def __init__(
         """Initializes access to analysis results."""
         self._path = path
         self._filename = filename
-        self._deps = deps  # list of summary jars registered as dependencies
+        self._deps = deps  # list of summary zips registered as dependencies
         self._header_ty: Type[HeaderTy] = fileformat  # currently supported: elf, pe
 
         self._userdata: Optional[UserData] = None
diff --git a/chb/cmdline/AnalysisManager.py b/chb/cmdline/AnalysisManager.py
index cd70751f..6a020842 100644
--- a/chb/cmdline/AnalysisManager.py
+++ b/chb/cmdline/AnalysisManager.py
@@ -88,7 +88,7 @@ def __init__(
         Arguments:
         - path: path of the directory that holds the target executable
         - filename: filename of the target executable
-        - deps: list of summary jars
+        - deps: list of summary zips
         - hints: Dictionary with items to add to the userdata file
         - elf/mips/arm: modifiers (default is x86 PE)
         """
@@ -455,7 +455,7 @@ def _analyze_until_stable(
             preamble_cutoff: int = 12) -> int:
         cwd = os.getcwd()
         os.chdir(self.path)   # temporary change in directory
-        functionsjarfile = UF.get_functionsjar_filename(self.path, self.filename)
+        functionszipfile = UF.get_functionszip_filename(self.path, self.filename)
         analysisdir = UF.get_analysis_dir(self.path, self.filename)
         cmd = [self.chx86_analyze, "-summaries", self.chsummaries]
         cmd.extend(["-preamble_cutoff", str(preamble_cutoff)])
@@ -510,7 +510,7 @@ def _analyze_until_stable(
             cmd.append("-fail_on_function_failure")
 
         cmd.extend(["-analyze", self.filename])
-        jarcmd = ["jar", "cf",  functionsjarfile, "-C", analysisdir, "functions"]
+        zipcmd = ["zip", "-r", functionszipfile, "functions"]
         print_progress_update("Analyzing "
               + self.filename
               + " (max "
@@ -543,8 +543,8 @@ def _analyze_until_stable(
                 or (count > iterations))
 
             if isfinished:
-                chklogger.logger.debug("execute command %s", " ".join(jarcmd))
-                subprocess.call(jarcmd, stderr=subprocess.STDOUT)
+                chklogger.logger.debug("execute zip command %s", " ".join(zipcmd))
+                subprocess.call(zipcmd, stderr=subprocess.STDOUT, cwd=analysisdir)
                 fincmd = cmd + ["-collectdata"]
                 if self.use_ssa:
                     fincmd = fincmd + ["-ssa"]
@@ -552,8 +552,8 @@ def _analyze_until_stable(
                     fincmd = fincmd + ["-no_varinvs"]
                 chklogger.logger.debug("execute command %s", " ".join(fincmd))
                 result = self._call_analysis(fincmd, timeout=timeout)
-                chklogger.logger.debug("execute command %s", " ".join(jarcmd))
-                subprocess.call(jarcmd, stderr=subprocess.STDOUT)
+                chklogger.logger.debug("execute zip command %s", " ".join(zipcmd))
+                subprocess.call(zipcmd, stderr=subprocess.STDOUT, cwd=analysisdir)
                 count += 1
                 (stable, results, r_update) = self._get_results()
                 print_progress_update(r_update + "  " + self.filename)
@@ -563,11 +563,12 @@ def _analyze_until_stable(
                 print("\n".join(lines))
                 return isstable == "yes"
 
-            chklogger.logger.debug("execute command %s", " ".join(jarcmd))
-            subprocess.call(jarcmd, stderr=subprocess.STDOUT)
+            chklogger.logger.debug("execute zip command %s", " ".join(zipcmd))
+            subprocess.call(zipcmd, stderr=subprocess.STDOUT, cwd=analysisdir)
             result = self._call_analysis(cmd, timeout=timeout)
             if result != 0:
-                chklogger.logger.debug("return cwd %s", cwd)
+                chklogger.logger.error("zip command failed with return code %s, "
+                                       "changing back to folder %s", result, cwd)
                 os.chdir(cwd)    # return to original directory
                 print("\n".join(lines))
                 return result
diff --git a/chb/cmdline/chkx b/chb/cmdline/chkx
index f9095d9f..6c9a6160 100755
--- a/chb/cmdline/chkx
+++ b/chb/cmdline/chkx
@@ -245,7 +245,7 @@ def summariescommand(args: argparse.Namespace) -> NoReturn:
 def summarieslistcommand(args: argparse.Namespace) -> NoReturn:
     print("The summaries list command provides access to function summaries.")
     print("It can be followed by the following subcommands:")
-    print("  dlls          output a list of dlls provided (per jarfile)")
+    print("  dlls          output a list of dlls provided (per zipfile)")
     print("  dll-functions <dll-1> ... <dll-n> output a list of functions for each dll listed")
     print("  so-functions  output a list of shared-object functions (ELF)")
     exit(0)
@@ -433,7 +433,7 @@ def parse() -> argparse.Namespace:
         '--thirdpartysummaries',
         nargs="*",
         default=[],
-        help='summary jars for third party libraries')
+        help='summary zips for third party libraries')
     analyzecmd.add_argument(
         "--so_libraries",
         nargs="*",
diff --git a/chb/cmdline/summariescmds.py b/chb/cmdline/summariescmds.py
index e8f19baa..0d1703cc 100644
--- a/chb/cmdline/summariescmds.py
+++ b/chb/cmdline/summariescmds.py
@@ -76,10 +76,10 @@ def summaries_dlls_cmd(args: argparse.Namespace) -> NoReturn:
     models = ModelsAccess()
 
     modeldlls = models.dlls()
-    for jar in modeldlls:
-        print(jar)
+    for zip_f in modeldlls:
+        print(zip_f)
         print("-" * 80)
-        for dll in sorted(modeldlls[jar]):
+        for dll in sorted(modeldlls[zip_f]):
             print("  " + dll)
         print("-" * 80)
     exit(0)
@@ -132,18 +132,18 @@ def summaries_so_functions_cmd(args: argparse.Namespace) -> NoReturn:
 
     models = ModelsAccess()
 
-    # returns a dictionary with so-functions for different jars
+    # returns a dictionary with so-functions for different zips
     sofunctions = models.all_so_function_summaries()
-    for jar in sorted(sofunctions):
+    for zip_f in sorted(sofunctions):
         print("\nShared object functions from "
-              + jar
+              + zip_f
               + " ("
-              + str(len(sofunctions[jar]))
+              + str(len(sofunctions[zip_f]))
               + ")")
         print("=" * 80)
         pdrcounter = 0
         pdwcounter = 0
-        for f in sorted(sofunctions[jar], key=lambda f: f.name):
+        for f in sorted(sofunctions[zip_f], key=lambda f: f.name):
             summary = models.so_function_summary(f.name)
             prec = summary.semantics.preconditions
             pdread = len([p for p in prec if p.is_deref_read])
@@ -155,7 +155,7 @@ def summaries_so_functions_cmd(args: argparse.Namespace) -> NoReturn:
                 pdwcounter += 1
         print("=" * 80)
 
-    total = sum(len(sofunctions[jar]) for jar in sofunctions)
+    total = sum(len(sofunctions[zip_f]) for zip_f in sofunctions)
     print(
         "\nTotal: "
         + str(total)
diff --git a/chb/models/JniFunctionSummaryLibrary.py b/chb/models/JniFunctionSummaryLibrary.py
index 6a9a1788..19f29c4f 100644
--- a/chb/models/JniFunctionSummaryLibrary.py
+++ b/chb/models/JniFunctionSummaryLibrary.py
@@ -40,7 +40,7 @@ class JniFunctionSummaryLibrary(L.FunctionSummaryLibrary):
 
     Native methods are indexed by numbers, roughly through 231. Many of these
     methods are similar, differring only in the type to which they are
-    applicable. The summaries in bchsummaries.jar make use of templates that
+    applicable. The summaries in the bchsummaries archive make use of templates that
     can be instantiated for these different types.
 
     For example, for jni_190.xml:
diff --git a/chb/models/ModelsAccess.py b/chb/models/ModelsAccess.py
index 907aea6f..a5a9dd5f 100644
--- a/chb/models/ModelsAccess.py
+++ b/chb/models/ModelsAccess.py
@@ -45,56 +45,56 @@ class ModelsAccess(object):
     """Main entry point for library function summaries.
 
     The main summary collection is obtained from the configured
-    bchummaries.jar. Other summary collections may be added via
-    additional jarfiles, specified with depjars.
+    bchummaries.zip. Other summary collections may be added via
+    additional zipfiles, specified with depzips.
     """
 
     def __init__(self,
-                 depjars: Sequence[str] = []) -> None:
-        """Initialize library models access with jarfile."""
-        self._bchsummariesjarfilename = Config().summaries
-        self._depjars = depjars
+                 depzips: Sequence[str] = []) -> None:
+        """Initialize library models access with zipfile."""
+        self._bchsummarieszipfilename = Config().summaries
+        self._depzips = depzips
         self._bchsummaries: Optional[SummaryCollection] = None
         self._dependencies: Sequence[SummaryCollection] = []
         self._dlls: Dict[str, Sequence[str]] = {}
         self._sofunctionsummaries: Dict[str, Sequence[FunctionSummary]] = {}
 
     @property
-    def depjars(self) -> Sequence[str]:
-        return self._depjars
+    def depzips(self) -> Sequence[str]:
+        return self._depzips
 
     @property
-    def bchsummariesjarfilename(self) -> str:
-        return self._bchsummariesjarfilename
+    def bchsummarieszipfilename(self) -> str:
+        return self._bchsummarieszipfilename
 
     @property
     def bchsummaries(self) -> SummaryCollection:
         if self._bchsummaries is None:
             self._bchsummaries = SummaryCollection(
-                self, self.bchsummariesjarfilename)
+                self, self.bchsummarieszipfilename)
         return self._bchsummaries
 
     @property
     def dependencies(self) -> Sequence[SummaryCollection]:
         if len(self._dependencies) == 0:
-            self._dependencies = [SummaryCollection(self, j) for j in self.depjars]
+            self._dependencies = [SummaryCollection(self, j) for j in self.depzips]
         return self._dependencies
 
     @property
     def stats(self) -> str:
         lines: List[str] = []
         dlls = self.dlls()
-        for jar in dlls:
-            lines.append(jar.ljust(20) + str(len(dlls[jar])) + " dlls")
+        for zip_f in dlls:
+            lines.append(zip_f.ljust(20) + str(len(dlls[zip_f])) + " dlls")
         return "\n".join(lines)
 
     def dlls(self) -> Mapping[str, Sequence[str]]:
-        """Return a mapping from jarfilename to list of function names."""
+        """Return a mapping from zipfilename to list of function names."""
 
         if len(self._dlls) == 0:
             self._dlls["bchsummaries"] = self.bchsummaries.dlls
             for d in self.dependencies:
-                self._dlls[d.jarfilename] = d.dlls
+                self._dlls[d.zipfilename] = d.dlls
         return self._dlls
 
     def has_dll_function_summary(self, dll: str, fname: str) -> bool:
@@ -140,7 +140,7 @@ def so_function_summary(self, fname: str) -> FunctionSummary:
         return self.bchsummaries.so_function_summary(fname)
 
     def all_so_function_summaries(self) -> Mapping[str, Sequence[FunctionSummary]]:
-        """Return a mapping from jarfilename to list of function summaries."""
+        """Return a mapping from zipfilename to list of function summaries."""
 
         if len(self._sofunctionsummaries) == 0:
             sosummaries = self.bchsummaries.all_so_function_summaries()
@@ -148,7 +148,7 @@ def all_so_function_summaries(self) -> Mapping[str, Sequence[FunctionSummary]]:
             for d in self.dependencies:
                 if d.has_so_functions():
                     self._sofunctionsummaries[
-                        d.jarfilename] = d.all_so_function_summaries()
+                        d.zipfilename] = d.all_so_function_summaries()
         return self._sofunctionsummaries
 
     def enum_definitions(self) -> Mapping[str, DllEnumDefinitions]:
diff --git a/chb/models/SummaryCollection.py b/chb/models/SummaryCollection.py
index 2f4ba055..67dfa064 100644
--- a/chb/models/SummaryCollection.py
+++ b/chb/models/SummaryCollection.py
@@ -51,15 +51,15 @@
 
 
 class SummaryCollection:
-    """Represents all summary entities in a single jar file."""
+    """Represents all summary entities in a single zip file."""
 
     def __init__(
             self,
             models: "ModelsAccess",
-            jarfilename: str) -> None:
+            zipfilename: str) -> None:
         self._models = models
-        self._jarfilename = jarfilename
-        self._jarfile = zipfile.ZipFile(self.jarfilename, "r")
+        self._zipfilename = zipfilename
+        self._zipfile = zipfile.ZipFile(self.zipfilename, "r")
         self._filenames: List[str] = []
         self._directorynames: List[str] = []
         self._dlls: List[str] = []
@@ -73,17 +73,17 @@ def models(self) -> "ModelsAccess":
         return self._models
 
     @property
-    def jarfile(self) -> zipfile.ZipFile:
-        return self._jarfile
+    def zipfile(self) -> zipfile.ZipFile:
+        return self._zipfile
 
     @property
-    def jarfilename(self) -> str:
-        return self._jarfilename
+    def zipfilename(self) -> str:
+        return self._zipfilename
 
     @property
     def filenames(self) -> List[str]:
         if len(self._filenames) == 0:
-            for info in self.jarfile.infolist():
+            for info in self.zipfile.infolist():
                 self._filenames.append(info.filename)
         return self._filenames
 
@@ -336,7 +336,7 @@ def retrieve_ref_jni_function_summary_xnode(
         raise UF.CHBError("Retrieval of jni references not implemented yet")
 
     def _get_summary_xnode(self, filename: str, tag: str) -> ET.Element:
-        zfile = self.jarfile.read(filename).decode('utf-8')
+        zfile = self.zipfile.read(filename).decode('utf-8')
         try:
             xnode = ET.fromstring(str(zfile)).find(tag)
         except ET.ParseError as e:
diff --git a/chb/util/fileutil.py b/chb/util/fileutil.py
index 4720eb10..7a5c8819 100644
--- a/chb/util/fileutil.py
+++ b/chb/util/fileutil.py
@@ -50,7 +50,7 @@
     x_global_state.xml
     x_global_locations.xml
     x_system_info.xml
-    x_functions.jar
+    x_functions.zip
     x_asm.log
     x_orphan.log
     x_bdict.log
@@ -637,8 +637,9 @@ def get_interface_dictionary_xnode(path: str, xfile: str) -> ET.Element:
     return get_chb_xnode(filename, "interface-dictionary")
 
 
-def get_functionsjar_filename(path: str, xfile: str) -> str:
+def get_functionszip_filename(path: str, xfile: str) -> str:
     fdir = get_analysis_dir(path, xfile)
+    # For now we keep the .jar extension until we update the ocaml analyzer
     return get_chb_filename(fdir, xfile, "functions.jar")