diff --git a/README.md b/README.md
index 9efb702..ef3e015 100644
--- a/README.md
+++ b/README.md
@@ -26,8 +26,8 @@ Ancypwn is now plugin based, choose your own plugin or write a new plugin if you
 
 You will need at least 4 parts to have a working environment (apart from docker).
 
-0. A ancypwn docker image, and is properly tagged as ancypwn:VERSION, VERSION is one of "16.04", "18.04" or "18.10", each represent a corresponding ubuntu version.
-1. ancypwn launcher (`pip install ancypwn`)
+0. A ancypwn docker image, and is properly tagged as ancypwn:VERSION, VERSION is one of "16.04", "18.04", "20.04" or "18.10", each represent a corresponding ubuntu version.
+1. ancypwn launcher (`pip3 install ancypwn`)
 2. a backend: backend provides ability to listen incoming request to pop up a terminal window, then asks terminal plugin to do it and does different docker container launching strategy (like remote support).
 3. a terminal plugin: this one handles terminal poping up
 
@@ -36,13 +36,11 @@ Backends have the name pattern: `ancypwn-backend-*`, while terminal plugin has t
 So you need:
 
 ```
-# download images, and tag them properly
-docker pull auxy233/ancypwn:16.04
-docker pull auxy233/ancypwn:18.04
-docker pull auxy233/ancypwn:18.10
-docker image tag auxy233/ancypwn:16.04 ancypwn:16.04
-docker image tag auxy233/ancypwn:18.04 ancypwn:18.04
-docker image tag auxy233/ancypwn:18.10 ancypwn:18.10
+# build images
+docker build -t ancypwn:20.04 .
+docker build -t ancypwn:18.04 .
+docker build -t ancypwn:18.10 .
+docker build -t ancypwn:16.04 .
 
 pip3 install ancypwn
 # pip3 install ancypwn-backend-* (choose your backend, and install it)
@@ -156,3 +154,4 @@ Current supported ubuntu version:
 * 18.10
 * 18.04
 * 16.04
+* 20.04
diff --git a/ancypwn-backend-unix b/ancypwn-backend-unix
new file mode 160000
index 0000000..f0a7ad5
--- /dev/null
+++ b/ancypwn-backend-unix
@@ -0,0 +1 @@
+Subproject commit f0a7ad5f0c6af66500dbcbad2593a3028fa36382
diff --git a/ancypwn-docker/16.04/Dockerfile b/ancypwn-docker/16.04/Dockerfile
index 5228725..700f4c0 100644
--- a/ancypwn-docker/16.04/Dockerfile
+++ b/ancypwn-docker/16.04/Dockerfile
@@ -1,49 +1,67 @@
-FROM ubuntu:16.04
-
-MAINTAINER Anciety <anciety512@gmail.com>
-
-# Apt packages
-RUN dpkg --add-architecture i386 && apt-get update && \
-    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
-    git nasm  python \
-    build-essential \
-    python-dev python-pip python-setuptools \
-    libc6-dbg \
-    libc6-dbg:i386 \
-    gcc-multilib \
-    gdb-multiarch \
-    gcc \
-    wget \
-    curl \
-    glibc-source \
-    cmake \
-    python-capstone \
-    socat \
-    netcat \
-    ruby \
-    ruby-dev \
-    lxterminal && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
-    cd ~ && tar -xvf /usr/src/glibc/glibc-2.23.tar.xz
-
-# python/ruby packages & gdb-plugin
-RUN pip install --no-cache-dir pwntools ropper ancypatch && \
-    gem install one_gadget seccomp-tools && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# git installaing package
-RUN cd ~/ && \
-    git clone https://github.com/pwndbg/pwndbg.git && \
-    cd ~/pwndbg/ && ./setup.sh && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-ENV LANG C.UTF-8
-
-COPY ./ancyterm.py /usr/local/bin/ancyterm
-RUN chmod +x /usr/local/bin/ancyterm
-
-VOLUME ["/pwn"]
-WORKDIR /pwn
-
-CMD ["/bin/bash"]
+FROM ubuntu:16.04
+
+MAINTAINER Anciety <anciety512@gmail.com>
+
+# Apt packages
+RUN dpkg --add-architecture i386 && \
+    apt-get update && \
+    apt-get -y install python-software-properties \
+    software-properties-common && \
+    add-apt-repository ppa:brightbox/ruby-ng && \
+    apt-get update && \
+    apt-get purge --auto-remove ruby && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
+    git nasm python3 \
+    build-essential \
+    python3-dev python3-pip python3-setuptools\
+    libc6-dbg \
+    libc6-dbg:i386 \
+    gcc-multilib \
+    gdb-multiarch \
+    gcc \
+    sudo \
+    wget \
+    curl \
+    glibc-source \
+    cmake \
+    socat \
+    netcat \
+    ruby2.6 \
+    ruby2.6-dev \
+    lxterminal && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    cd ~ && tar -xvf /usr/src/glibc/glibc-2.23.tar.xz
+
+# python/ruby packages & gdb-plugin
+#RUN wget https://files.pythonhosted.org/packages/cd/82/04e9aaf603fdbaecb4323b9e723f13c92c245f6ab2902195c53987848c78/pip-21.1.2-py3-none-any.whl && \
+#RUN pip3 install pip-21.1.2-py3-none-any.whl && \
+RUN wget https://bootstrap.pypa.io/pip/3.5/get-pip.py && \
+    python3 get-pip.py && \
+#    pip3 install --upgrade pip && \
+    pip3 install --no-cache-dir pwntools ropper ancypatch LibcSearcher&& \
+    gem install one_gadget seccomp-tools && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+# git installaing package
+RUN cd ~/ && \
+    git clone https://github.com/pwndbg/pwndbg.git && \
+    cd ~/pwndbg/ && ./setup.sh && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+RUN cd ~/ && \
+    git clone https://github.com/scwuaptx/Pwngdb.git && \
+    cp ~/Pwngdb/.gdbinit ~/ && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    sed -i '1d' ~/.gdbinit && \
+    sed -i '1c source ~/pwndbg/gdbinit.py' ~/.gdbinit
+
+ENV LANG C.UTF-8
+
+COPY ./ancyterm.py /usr/local/bin/ancyterm
+RUN chmod +x /usr/local/bin/ancyterm
+
+VOLUME ["/pwn"]
+WORKDIR /pwn
+
+CMD ["/bin/bash"]
diff --git a/ancypwn-docker/18.04/Dockerfile b/ancypwn-docker/18.04/Dockerfile
index 072c315..1221cd0 100644
--- a/ancypwn-docker/18.04/Dockerfile
+++ b/ancypwn-docker/18.04/Dockerfile
@@ -1,50 +1,61 @@
-FROM ubuntu:18.04
-
-MAINTAINER Anciety <anciety512@gmail.com>
-
-
-# Apt packages
-RUN dpkg --add-architecture i386 && apt-get update && \
-    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
-    git nasm  python \
-    build-essential \
-    python-dev python-pip python-setuptools \
-    libc6-dbg \
-    libc6-dbg:i386 \
-    gcc-multilib \
-    gdb-multiarch \
-    gcc \
-    wget \
-    curl \
-    glibc-source \
-    cmake \
-    python-capstone \
-    socat \
-    netcat \
-    ruby \
-    ruby-dev \
-    lxterminal && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
-    cd ~ && tar -xvf /usr/src/glibc/glib*.tar.xz
-
-# python/ruby packages & gdb-plugin
-RUN pip install --no-cache-dir pwntools ropper ancypatch && \
-    gem install one_gadget seccomp-tools && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# git installaing package
-RUN cd ~/ && \
-    git clone https://github.com/pwndbg/pwndbg.git && \
-    cd ~/pwndbg/ && ./setup.sh && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-ENV LANG C.UTF-8
-
-COPY ./ancyterm.py /usr/local/bin/ancyterm
-RUN chmod +x /usr/local/bin/ancyterm
-
-VOLUME ["/pwn"]
-WORKDIR /pwn
-
-CMD ["/bin/bash"]
+FROM ubuntu:18.04
+
+MAINTAINER Anciety <anciety512@gmail.com>
+
+
+# Apt packages
+RUN dpkg --add-architecture i386 && \
+    apt-get update && \
+    apt-get -y install sudo wget cmake curl gcc socat\
+    software-properties-common && \
+    wget http://archive.ubuntu.com/ubuntu/pool/main/k/keyutils/libkeyutils1_1.5.9-9.2ubuntu2_amd64.deb && \
+    dpkg -i libkeyutils1_1.5.9-9.2ubuntu2_amd64.deb && \
+    add-apt-repository ppa:brightbox/ruby-ng && \
+    apt-get update && \
+    apt-get purge --auto-remove ruby && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
+    git nasm python3 \
+    build-essential \
+    python3-dev python3-pip python3-setuptools \
+    libc6-dbg \
+    libc6-dbg:i386 \
+    gcc-multilib \
+    gdb-multiarch \
+    glibc-source \
+    netcat \
+    ruby2.6 \
+    ruby2.6-dev \
+    lxterminal && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    cd ~ && tar -xvf /usr/src/glibc/glib*.tar.xz
+
+# python/ruby packages & gdb-plugin
+RUN wget https://bootstrap.pypa.io/pip/3.5/get-pip.py && \
+    python3 get-pip.py && \
+    pip install --no-cache-dir LibcSearcher pwntools ropper ancypatch && \
+    gem install one_gadget seccomp-tools && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+# git installaing package
+RUN cd ~/ && \
+    git clone https://github.com/pwndbg/pwndbg.git && \
+    cd ~/pwndbg/ && ./setup.sh && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+RUN cd ~/ && \
+    git clone https://github.com/scwuaptx/Pwngdb.git && \
+    cp ~/Pwngdb/.gdbinit ~/ && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    sed -i '1d' ~/.gdbinit && \
+    sed -i '1c source ~/pwndbg/gdbinit.py' ~/.gdbinit*
+
+ENV LANG C.UTF-8
+
+COPY ./ancyterm.py /usr/local/bin/ancyterm
+RUN chmod +x /usr/local/bin/ancyterm
+
+VOLUME ["/pwn"]
+WORKDIR /pwn
+
+CMD ["/bin/bash"]
diff --git a/ancypwn-docker/18.10/Dockerfile b/ancypwn-docker/18.10/Dockerfile
index 6af97e6..1e5d3e9 100644
--- a/ancypwn-docker/18.10/Dockerfile
+++ b/ancypwn-docker/18.10/Dockerfile
@@ -1,49 +1,49 @@
-FROM ubuntu:18.10
-
-MAINTAINER Anciety <anciety512@gmail.com>
-
-# Apt packages
-RUN dpkg --add-architecture i386 && apt-get update && \
-    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
-    git nasm  python \
-    build-essential \
-    python-dev python-pip python-setuptools \
-    libc6-dbg \
-    libc6-dbg:i386 \
-    gcc-multilib \
-    gdb-multiarch \
-    gcc \
-    wget \
-    curl \
-    glibc-source \
-    cmake \
-    python-capstone \
-    socat \
-    netcat \
-    ruby \
-    ruby-dev \
-    lxterminal && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
-    cd ~ && tar -xvf /usr/src/glibc/glibc-*.tar.xz
-
-# python/ruby packages & gdb-plugin
-RUN pip install --no-cache-dir pwntools ropper ancypatch && \
-    gem install one_gadget seccomp-tools && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# git installaing package
-RUN cd ~/ && \
-    git clone https://github.com/pwndbg/pwndbg.git && \
-    cd ~/pwndbg/ && ./setup.sh && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-ENV LANG C.UTF-8
-
-COPY ./ancyterm.py /usr/local/bin/ancyterm
-RUN chmod +x /usr/local/bin/ancyterm
-
-VOLUME ["/pwn"]
-WORKDIR /pwn
-
-CMD ["/bin/bash"]
+FROM ubuntu:18.10
+
+MAINTAINER Anciety <anciety512@gmail.com>
+
+# Apt packages
+RUN dpkg --add-architecture i386 && apt-get update && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
+    git nasm  python \
+    build-essential \
+    python-dev python-pip python-setuptools \
+    libc6-dbg \
+    libc6-dbg:i386 \
+    gcc-multilib \
+    gdb-multiarch \
+    gcc \
+    wget \
+    curl \
+    glibc-source \
+    cmake \
+    python-capstone \
+    socat \
+    netcat \
+    ruby \
+    ruby-dev \
+    lxterminal && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    cd ~ && tar -xvf /usr/src/glibc/glibc-*.tar.xz
+
+# python/ruby packages & gdb-plugin
+RUN pip install --no-cache-dir pwntools ropper ancypatch && \
+    gem install one_gadget seccomp-tools && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+# git installaing package
+RUN cd ~/ && \
+    git clone https://github.com/pwndbg/pwndbg.git && \
+    cd ~/pwndbg/ && ./setup.sh && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+ENV LANG C.UTF-8
+
+COPY ./ancyterm.py /usr/local/bin/ancyterm
+RUN chmod +x /usr/local/bin/ancyterm
+
+VOLUME ["/pwn"]
+WORKDIR /pwn
+
+CMD ["/bin/bash"]
diff --git a/ancypwn-docker/20.04/Dockerfile b/ancypwn-docker/20.04/Dockerfile
new file mode 100644
index 0000000..05a613e
--- /dev/null
+++ b/ancypwn-docker/20.04/Dockerfile
@@ -0,0 +1,63 @@
+FROM ubuntu:20.04
+
+MAINTAINER xibai <kirito_xibai@qq.com>
+
+# Apt packages
+RUN dpkg --add-architecture i386 && apt-get update && \
+    apt-get -y install software-properties-common && \
+    add-apt-repository ppa:brightbox/ruby-ng && \
+    add-apt-repository ppa:deadsnakes/ppa && \
+    apt-get update && \
+    apt-get purge --auto-remove ruby && \
+    DEBIAN_FRONTEND=noninteractive apt-get install -qy \
+    git nasm python3 \
+    build-essential fakeroot dpkg-dev libcurl4-openssl-dev\
+    python3-dev python3-pip python3-setuptools \
+    libc6-dbg \
+    libc6-dbg:i386 \
+    gcc-multilib \
+    gdb-multiarch \
+    gcc \
+    wget \
+    curl \
+    glibc-source \
+    cmake \
+    socat \
+    sudo \
+    netcat \
+    ruby2.6 \
+    ruby2.6-dev \
+    lxterminal && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    cd ~ && tar -xvf /usr/src/glibc/glib*.tar.xz
+
+# python/ruby packages & gdb-plugin
+RUN wget https://bootstrap.pypa.io/pip/get-pip.py && \
+    python3 get-pip.py && \
+    pip3 install --no-cache-dir pwntools ropper ancypatch && \
+    gem install one_gadget seccomp-tools && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+# git installaing package
+RUN cd ~/ && \
+    git clone https://github.com/pwndbg/pwndbg.git && \
+    cd ~/pwndbg/ && ./setup.sh && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+RUN cd ~/ && \
+    git clone https://github.com/scwuaptx/Pwngdb.git && \
+    cp ~/Pwngdb/.gdbinit ~/ && \
+    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
+    sed -i '1d' ~/.gdbinit && \
+    sed -i '1c source ~/pwndbg/gdbinit.py' ~/.gdbinit
+
+ENV LANG C.UTF-8
+
+COPY ./ancyterm.py /usr/local/bin/ancyterm
+RUN chmod +x /usr/local/bin/ancyterm
+
+VOLUME ["/pwn"]
+WORKDIR /pwn
+
+CMD ["/bin/bash"]
diff --git a/ancypwn-terminal-iterm2 b/ancypwn-terminal-iterm2
new file mode 160000
index 0000000..0b14058
--- /dev/null
+++ b/ancypwn-terminal-iterm2
@@ -0,0 +1 @@
+Subproject commit 0b14058199862705e850e71007eb7be0f59e9655
diff --git a/ancypwn-terminal/ancyterm.py b/ancypwn-terminal/ancyterm.py
index 99b06e8..168e22d 100755
--- a/ancypwn-terminal/ancyterm.py
+++ b/ancypwn-terminal/ancyterm.py
@@ -1,4 +1,5 @@
 #!/usr/bin/python
+# -*- coding: UTF-8 -*-
 
 import argparse
 import json
@@ -10,32 +11,28 @@ def pack(num):
     return struct.pack('<I', num)
 
 
+# 这个主要是用来传递终端参数的,执行的命令，和选择的终端信息。
 def main():
     parser = argparse.ArgumentParser('fake terminal that connects to outside world')
     parser.add_argument('-e', required=True, help='execute command in outside terminal')
     parser.add_argument('-t', '--terminal', required=True, help='terminal execute command')
     parser.add_argument('-p', '--port', type=int, help='port used outside')
     parser.add_argument('-s', '--server', required=True, help='host server')
-
     args = parser.parse_args()
-
     cmd = args.e
     terminal = args.terminal
     port = args.port if not args.port is None else 15111
     server = args.server
-
     msg = {
         'exec': cmd,
         'terminal': args.terminal
     }
     msg_json = json.dumps(msg)
     length = len(msg_json)
-    protocol_msg = pack(length) + msg_json
-
+    protocol_msg = pack(length) + str.encode(msg_json)
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-    sock.connect((args.server, port))
-
-    sock.sendall(protocol_msg)
+    sock.connect((args.server, port)) #连接服务器
+    sock.sendall(protocol_msg)  #发送数据
     
 
 if __name__ == '__main__':
diff --git a/src/ancypwn.py b/src/ancypwn.py
index f0f28bd..a12d8c7 100644
--- a/src/ancypwn.py
+++ b/src/ancypwn.py
@@ -10,20 +10,20 @@
 APPNAME = 'ancypwn'
 APPAUTHOR = 'Anciety'
 
-
-CONFIG_DIR = appdirs.user_data_dir(APPNAME, APPAUTHOR)
-CONFIG_FILE_PATH = os.path.join(CONFIG_DIR, 'config.json')
+CONFIG_DIR = appdirs.user_data_dir(APPNAME, APPAUTHOR) 
+CONFIG_FILE_PATH = os.path.join(CONFIG_DIR, 'config.json') 
 
 
 SUPPORTED_UBUNTU_VERSION = [
     '16.04',
     '18.04',
-    '18.10',
+    '18.10', # This is not well maintained because it is not commonly used 
+    '20.04',
 ]
 
 
 system = platform.system().lower()
-if 'linux' in system or 'darwin' in system:
+if 'linux' in system or 'darwin' in system: 
     BACKEND_DEFAULT_CONFIG = {
         'name': 'unix'
     }
@@ -40,7 +40,7 @@
     install_plugin_name = 'windows'
 
 
-DEFAULT_CONFIG = {
+DEFAULT_CONFIG = { 
     'terminal_port': 15111,
     'backend': BACKEND_DEFAULT_CONFIG,
     # install plugin name
@@ -58,7 +58,7 @@ class PluginNotFoundError(Exception):
 
 def plugin_module_import(name):
     try:
-        return importlib.import_module(name)
+        return importlib.import_module(name) 
     except ModuleNotFoundError as e:
         prompt = 'plugin {} not found, please install it first.\n'.format(name)
         prompt += 'try follwing:\n\tpip3 install {}'.format(name)
@@ -70,17 +70,17 @@ def __init__(self, config):
         name = config['install_plugin']
         realname = 'ancypwn_install_{}'.format(name)
         self.config = config
-        self.mod = plugin_module_import(realname)
+        self.mod = plugin_module_import(realname) 
 
     def install(self):
-        self.mod.install(self.config)
+        self.mod.install(self.config) 
 
 
 class Backend:
     def __init__(self, config):
-        realname = 'ancypwn_backend_{}'.format(config['backend']['name'])
+        realname = 'ancypwn_backend_{}'.format(config['backend']['name']) #macos ancypwn_backend_unix
         self.config = config
-        self.mod = plugin_module_import(realname)
+        self.mod = plugin_module_import(realname) 
 
     def run(self, directory=None, priv=None, image=None, tag=None, command=None):
         if directory is None or \
@@ -91,7 +91,7 @@ def run(self, directory=None, priv=None, image=None, tag=None, command=None):
             # this should never hapen
             raise Exception('backend run argument incorrect!')
         image_name = '{}:{}'.format(image, tag)
-        self.mod.run(
+        self.mod.run(  
             config=self.config,
             priv=priv,
             image_name=image_name,
diff --git a/src/server.py b/src/server.py
index 907a5ed..07027ce 100644
--- a/src/server.py
+++ b/src/server.py
@@ -17,17 +17,17 @@ def plugin_module_import(name):
 
 class NotificationHandler(StreamRequestHandler):
     def handle(self):
-        length = struct.unpack('<I', self.request.recv(4))[0]
-        json_content = self.request.recv(length)
+        length = struct.unpack('<I', self.request.recv(4))[0] 
+        json_content = self.request.recv(length) 
         content = json.loads(json_content)
         terminal = content['terminal']
-        if content['exec'] != '':
+        if content['exec'] != '': 
             command = 'ancypwn attach -c \'{}\''.format(content['exec'])
         else:
             command = 'ancypwn attach'
         realname = 'ancypwn_terminal_{}'.format(terminal)
-        mod = plugin_module_import(realname)
-        mod.run(command)
+        mod = plugin_module_import(realname) 
+        mod.run(command) 
 
 
 class ServerProcess(multiprocessing.Process):
diff --git a/src/util.py b/src/util.py
index 367d1c0..1543455 100644
--- a/src/util.py
+++ b/src/util.py
@@ -2,9 +2,9 @@
 import pathlib
 
 def _make_sure_directory(path):
-    directory = os.path.dirname(path)
+    directory = os.path.dirname(path)  
 
-    if not os.path.exists(directory):
+    if not os.path.exists(directory): 
         pathlib.Path(directory).mkdir(parents=True, exist_ok=True)