Kali Linux is a popular Linux distribution and widely used for penetration testing of software and ethical hacking. It has an astronomically higher amount of commands and tools for various purposes. A Kali Linux cheat sheet can be handy for quickly accessing these commands and finding the most useful ones.
Download Kali Linux Commands Cheat Sheet
What is Kali Linux?
Kali Linux is a Debian-based Linux distro developed by Offensive Security for penetration testing, advanced forensics and security auditing etc. It has highly customizable tools and commands that include network analyzer, password cracking tools, wireless network scanners, vulnerability scanners and so on. In a word, Kali Linux is the default OS for cybersecurity professionals.
Kali Linux Commands Cheat Sheet
Kali Linux commands cheat sheet contains many types of commands for Information Gathering, Vulnerability Analysis, and many more. Here is a list of frequently used commands of kali Linux that can be often useful for kali Linux users.
Kali Linux Commands for Information Gathering
Kali Linux has the most extensive collection of information gathering tools and commands. These are useful for gathering information about a target system and networks. The following list has some most used tools and commands of this type.
| Command |
Description |
| ACE-voip |
Detect and analyze voice-over IP traffic |
| Amap |
Identify open ports and services on a remote system |
| APT2 |
Automatic penetration testing and regenerating reports |
| arp-scan |
Discover hosts on a network |
| Automater |
Automatic OSINT gathering |
| bing-ip2hosts |
Enumerate hostnames from Bing search result |
| braa |
Detect and analyze broadcast radio signals |
| CaseFile |
Create and manage threat intelligence reports |
| CDPSnarf |
Extract CDP information from a network |
| copy-router-config |
Backing up router configurations or transferring configurations to a new router |
| DMitry |
Gather target network information including port scanning and WHOIS lookups |
| dnmap |
Identify hosts and services on a network |
| dnsenum |
Gather information about DNS records including subdomains |
| dnsmap |
Identify active DNS servers and associated hostnames |
| DNSRecon |
DNS reconnaissance tool to gather information about servers, zone transfer and IP addresses |
| dnstracer |
Trace DNS queries to identify problems and misconfigurations |
| dnswalk |
Check common DNS misconfiguration |
| DotDotPwn |
Exploit directory traversal vulnerabilities |
| enum4linux |
Gather information from Windows and Samba systems including shares, users and passwords |
| enumIAX |
Gather information from IAX-based VoIP systems |
| EyeWitness |
Generate screenshots of web applications |
| Faraday |
Manage and collaborate on vulnerability scans and security assessment |
| Fierce |
Identify non-contiguous IP space and map network infrastructure |
| Firewalk |
Determine specific traffic blocking by firewall and by analyzing TTl values |
| fragroute/fragrouter |
Intercept and modify network traffic at IP fragmentation level |
| Ghost Phisher |
Security testing for phishing attacks |
| GoLismero |
Web security testing tool |
| goofile |
Search specific file types on a target domain |
| ident-user-enum |
Identify user accounts on systems that use the Ident protocol |
| InSpy |
LinkedIn reconnaissance tool to gather information about employees, companies and job postings |
| InTrace |
Trace the route of TCP packets through a network |
| iSMTP |
Test the security of SMYP servers |
| lbd |
Identify load balancers and web application firewalls |
| Maltego Teeth |
Identify connections and relationships between entities |
| masscan |
A fast port scanner used for vulnerability assessment |
| Metagoofil |
Gather information and extract metadata from public documents |
| Miranda |
Tool for exploiting UPnP devices |
| nbtscan-unixwiz |
Scan NetBIOS nameservers to gather information about connected devices |
| Nikto |
Web server scanner |
| ntop |
Network traffic monitoring and analysis |
| OSRFramework |
Intelligence gathering framework used for data mining |
| p0f |
Passive network traffic analysis for identifying the operating systems and applications used on networked devices |
| Parsero |
Identify input validation-related vulnerabilities of web applications |
| SET |
Tool for performing social engineering attacks, password attacks etc. |
| SMBMap |
Enumerate and scan SMB shares |
| smtp-user-enum |
Enumerate usernames on a target SMTP server |
| snmp-check |
Enumerate and check the security of SNMP devices |
| SPARTA |
Graphical interface for network infrastructure penetration testing |
| sslcaudit |
Audit SSl/Tls certificates on a web server |
| SSLsplit |
Intercept and decrypt SSL/TLS traffic |
| sslstrip |
Tool for performing man-in-the-middle attacks on SSL/TLS encrypted connections |
| SSLyze |
Test SSL/TLS servers and clients |
| Sublist3r |
Enumerate subdomains of a target domain using search engines |
| THC-IPV6 |
Attack and test IPv6 networks |
| theHarvester |
Gather information on a target domain from various public sources |
| TLSSLed |
Evaluate the security of SSL/TLS connections |
| twofi |
Find potential usernames and passwords from Twitter |
| Unicornscan |
A fast and powerful network scanning tool |
| URLCrazy |
Generate and test domain typos and variations |
| Wireshark |
Network protocol analyzer for capturing and analyzing network traffic |
| WOL-E |
Tool for Wake-On-LAN attacks and network discovery |
| Xplico |
Extract application data from network traffic |
Kali Linux Commands for Vulnerability Analysis
Vulnerability analysis tools and commands in Kali Linux help identify the vulnerability in systems and networks, test the strength of passwords, and simulate attacks to determine potential weaknesses. Here is a list of popular tools and commands that are frequently used for vulnerability analysis.
| Command |
Description |
| BBQSQL |
A blind SQL injection and exploitation tool |
| BED |
A network protocol fuzzing tool |
| cisco-global-exploiter |
Exploit vulnerabilities in Cisco devices |
| cisco-ocs |
Scan and exploit Cisco devices |
| cisco-torch |
Test and scan the security of Cisco devices |
| copy-router-config |
Back up and restore Cisco router configurations |
| Doona |
Test the security of network devices and protocols |
| DotDotPwn |
Exploit directory traversal vulnerabilities |
| HexorBase |
A database management and exploitation tool |
| jSQL Injection |
A SQL injection exploitation tool |
| Lynis |
A security auditing and hardening tool for Linux and Unix-based systems |
| Nmap |
Network exploration and security auditing tool |
| ohrwurm |
A local root exploitation tool |
| openvas |
A vulnerability scanner and management tool |
| Oscanner |
Scan Oracle databases for vulnerabilities |
| Powerfuzzer |
A web application fuzzing and discovery tool |
| sfuzz |
A protocol fuzzer and vulnerability scanner |
| SidGuesser |
Identify valid user accounts in Windows domains |
| SIPArmyKnife |
Test the security of VoIP systems |
| sqlmap |
A SQL injection exploitation tool |
| Sqlninja |
A SQL server injection and takeover tool |
| sqlsus |
Identify and exploit SQL injection vulnerabilities |
| tnscmd10g |
Test and exploit Oracle TNS Listener vulnerabilities |
| unix-privesc-check |
Identify privilege escalation vulnerabilities in Unix-based systems |
| Yersinia |
Network protocol analyzer and attack tool for testing network security |
Kali Linux Commands for Wireless Attacks
Different techniques such as sniffing, spoofing, and cracking of wireless encryption protocols can be used for wireless attacks. There are a lot of commands and tools in Kali Linux for applying these techniques. The following list contains the most useful ones.
| Command |
Description |
| Airbase-ng |
Configure and attack wireless access points |
| Aircrack-ng |
Audit and test wireless network |
| Airdecap-ng and Airdecloak-ng |
Decrypt and deobfuscate captured wireless traffic |
| Aireplay-ng |
Inject traffic to wireless networks to test their security |
| airgraph-ng |
Generate graphs from wireless network data |
| Airmon-ng |
Enable and Disable monitor mode on wireless interfaces |
| Airodump-ng |
Capture wireless traffic and analyze it |
| airodump-ng-oui-update |
Update the OUI databases used by airodump-ng |
| Airolib-ng |
Manage and crack password hashes for WPA and WPA2 |
| Airserv-ng |
Run a wireless access point on a Linux system |
| Airtun-ng |
Create encrypted tunnels over wireless networks |
| Asleap |
Crack MS-CHAPv1 and MS-CHAPv2 authentication protocols |
| Besside-ng |
Capture and crack WEP and WPA-encrypted wireless traffic |
| Bluelog |
Scan and log Bluetooth devices |
| BlueMaho |
Discover and attack Bluetooth devices |
| Bluepot |
Simulate Bluetooth honeypots to detect and track attackers |
| BlueRanger |
Control Bluetooth devices remotely |
| Bluesnarfer |
Exploit Bluetooth vulnerabilities and gain unauthorized access to devices |
| Bully |
Brute-forcing WPS pins to gain access to wireless networks |
| coWPAtty |
Crack pre-shared keys for WPA-PSK networks |
| crackle |
Crack encrypted Bluetooth traffic |
| eapmd5pass |
Crack MD5 hashes of EAP passwords |
| Easside-ng |
Crack WEP and WPA-encrypted wireless traffic |
| Fern Wifi Cracker |
Audit and crack wireless networks |
| FreeRADIUS-WPE |
Exploit weak credentials in the FreeRADIUS server |
| Ghost Phisher |
Create phishing attacks on wireless networks |
| GISKismet |
Map and analyze wireless networks using GPS data |
| Gqrx |
A receiver for exploring wireless signals |
| gr-scan |
scan and decode various radio signals |
| hostapd-wpe |
Test and exploit the WPE feature in Hostpad |
| ivstools |
Convert and manipulate IVs for WEP cracking |
| kalibrate-rtl |
Calibrate the frequency offset of RTL-SDR dongles |
| KillerBee |
Explore and exploit ZigBee and IEEE 802.15.4 networks |
| Kismet |
Detect and analyze wireless networks |
| makeivs-ng |
Generate and inject fake IVs for WEP cracking |
| mdk3 |
Attack wireless networks by flooding them with de-authentication, disassociation, and other packets |
| mfcuk |
Crack Mifare Classic RFID cards |
| mfoc |
Crack Mifare Classic RFID cards |
| mfterm |
Interact with RFID cards |
| Multimon-NG |
Decode various radio signals |
| Packetforge-ng |
Create and inject custom packets into wireless networks |
| PixieWPS |
Exploit the WPS design flaw to recover WPA/WPA2 passwords |
| Pyrit |
Perform advanced WPA/WPA2 password cracking using GPU power |
| Reaver |
A tool for brute-forcing WPS |
| redfang |
A Bluetooth scanner and vulnerability assessment tool |
| RTLSDR Scanner |
A radio scanner for spectrum analysis and monitoring |
| Spooftooph |
A tool for Bluetooth device spoofing and cloning |
| Tkiptun-ng |
WPA encryption key recovery using TKIP vulnerabilities |
| Wesside-ng |
Automated wireless network hacking for WEP, WPA and WPA2 encryption |
| Wifi Honey |
Perform honey spot attacks on wireless networks |
| wifiphisher |
Steal credentials of wireless network |
| Wifitap |
Create virtual wireless access points and monitor network traffic |
| Wifite |
Audit and attack the automated wireless network |
| wpaclean |
Filter and clean WPA/WPA2 handshake capture file |
Kali Linux Forensics Tools
There are a lot of specially designed tools and commands for digital forensics investigations pre-installed in Kali Linux. These allow forensic analysts to acquire, analyze, and preserve digital forensic evidence quite efficiently. Here is a brief list of these types of tools and commands.
| Command |
Description |
| Binwalk |
Analyze and extract firmware images |
| bulk-extractor |
Extract artifacts from binary files |
| Capstone |
A multi-platform, multi-architecture disassembly framework |
| chntpw |
Reset passwords on Windows systems |
| Cuckoo |
An automated malware analysis system |
| dc3dd |
A tool for imaging and wiping hard drives |
| ddrescue |
Rescuing data from damaged disks |
| DFF |
A forensic framework for analyzing digital evidence |
| diStorm3 |
A disassembler library for x86/AMD64 |
| Dumpzilla |
Analyze Mozilla browser history |
| extundelete |
Recover deleted files from ext3/ext4 partitions |
| Foremost |
Extract files from disk images |
| Galleta |
Analyze browser cookies |
| Guymager |
Create forensic images |
| iPhone Backup Analyzer |
Analyze iPhone backups. |
| p0f |
A tool for passive OS fingerprinting and network analysis |
| pdf-parser |
A tool for analyzing PDF files |
| pdfid |
Analyze and detect malicious PDF files |
| pdgmail |
Analyze Gmail artifacts |
| peepdf |
Analyze and explore PDF files |
| RegRipper |
Analyze Windows registry hives |
| Volatility |
Analyze memory dumps |
Kali Linux Exploitation Tools
You can employ the exploitation tools of Kali Linux to develop and execute a wide range of exploits, from simple command injection attacks to complex remote code execution exploits. The following list contains most used exploitation tools of Kali Linux.
| Command |
Description |
| Armitage |
A graphical cyber attack management tool |
| Backdoor Factory |
Add backdoors to binaries |
| BeEF |
Penetration testing focuses on browser-based attacks |
| Commix |
A command injection exploitation tool |
| crackle |
Break Bluetooth Smart encryption |
| exploitdb |
A database of known exploits and vulnerable software |
| jboss-autopwn |
Exploit vulnerabilities in JBoss servers |
| MSFPC |
Create Metasploit payloads |
| RouterSploit |
Test vulnerabilities in routers and other embedded devices |
| ShellNoob |
Generate shellcode and convert shellcode to assembly |
Kali Linux Hardware Hacking Tools
The hardware hacking tools and commands are useful to identify and exploit vulnerabilities in various hardware devices. The list below contains a few of those.
| Command |
Description |
| android-sdk |
A software development kit for developing Android applications |
| Arduino |
An open-source electronics platform for creating interactive projects |
| dex2jar |
Convert Android DEX files to Java JAR files |
| Sakis3G |
Connect to 3G mobile networks |
| smali |
An assembler/disassembler for Android’s dex format |
Reverse Engineering in Kali Linux
In Kali Linux, there are several powerful tools and commands available for reverse engineering tasks. You can use these to disassemble, decompile, and analyze binaries. Here is a short list of a few of those.
| Command |
Description |
| apktool |
Reverse engineer and modify Android APK files |
| diStorm3 |
A disassembler library used for binary analysis |
| edb-debugger |
A cross-platform debugger for x86, ARM, MIPS, and PowerPC executables |
| jad |
Analyze and reverse engineer Java bytecode |
| javasnoop |
Intercept and analyze Java method calls |
| JD-GUI |
Decompile and analyze Java bytecode |
| OllyDbg |
A 32-bit assembler-level analyzing debugger |
| Valgrind |
Debug and profile Linux programs |
| YARA |
Match patterns and identify malware and other suspicious files |
Web Applications in Kali Linux
There are various tasks including identifying web vulnerabilities, misconfiguration, and security issues in web applications. Kali Linux is well-equipped to handle all of these. You can frequently use the following commands and tools to handle different issues related to web applications.
| Command |
Description |
| apache-users |
Find usernames on an Apache web server |
| Arachni |
A feature-rich web application security scanner |
| BlindElephant |
Identify the web application’s version number |
| Burp Suite |
Web application testing framework |
| CutyCapt |
Capture website screenshots |
| DAVTest |
Test the security of WebDAV servers |
| deblaze |
Discover hidden files and directories on a web server |
| DIRB |
A tool used for web content discovery |
| DirBuster |
A multi-threaded web application scanner |
| fimap |
Automate web application attacks and vulnerability scanning |
| FunkLoad |
A web functional testing and load testing tool |
| Gobuster |
Brute forcing directories and files on web servers |
| Grabber |
Detect security vulnerabilities of web applications |
| hURL |
A tool used for web application testing and discovery |
| jboss-autopwn |
Exploit vulnerable JBoss application servers |
| joomscan |
Identify vulnerabilities in Joomla! CMS |
| PadBuster |
Test Padding Oracle vulnerabilities in web applications |
| Paros |
A web application testing proxy used to intercept and analyze web traffic |
| Parsero |
A tool used for web application fingerprinting and directory discovery |
| plecost |
A WordPress vulnerability scanner |
| Powerfuzzer |
A highly automated web application vulnerability scanner |
| ProxyStrike |
Attack web applications through proxies |
| Recon-ng |
A web reconnaissance framework |
| Skipfish |
A web application security scanner used for reconnaissance and discovery |
| ua-tester |
Test user-agent strings in web applications |
| Uniscan |
Security scanner used for finding vulnerabilities |
| w3af |
A framework used for web application security testing |
| WebScarab |
A Java-based web application testing proxy used for intercepting and analyzing web traffic |
| Webshag |
A multi-threaded, multi-platform web application vulnerability scanner |
| WebSlayer |
Find vulnerabilities in web applications |
| WebSploit |
A web application security testing framework |
| Wfuzz |
A web application fuzzer used for brute forcing directories and files on web servers |
| WhatWeb |
Fingerprint web servers and identify vulnerabilities |
| WPScan |
A WordPress vulnerability scanner |
| XSSer |
Find and exploit XSS vulnerabilities |
Stress Testing in Kali Linux
Stress testing is crucial and depicts the resilience of a system against any cyber-attacks. A few commands and tools of Kali Linux related to stress testing are listed below.
| Command |
Description |
| DHCPig |
Flood DHCP servers with requests, causing them to crash or become unavailable |
| iaxflood |
Flood SIP servers with requests, causing them to crash or become unavailable |
| Inundator |
Flood a network with random packets, causing network congestion and slowdowns |
| inviteflood |
Flood SIP servers with INVITE requests, causing them to crash or become unavailable |
| ipv6-toolkit |
Collection of tools for testing and exploiting IPv6 networks |
| rtpflood |
Flood VoIP servers with RTP packets, causing them to crash or become unavailable |
| SlowHTTPTest |
Test the vulnerability of web servers to Slow HTTP |
| t50 |
Generate network traffic and test the performance of network devices under heavy loads |
| Termineter |
Test the security of Smart Grid devices and protocols |
| THC-SSL-DOS |
Flood SSL servers with SSL handshake requests, causing them to crash or become unavailable |
Sniffing & Spoofing in Kali Linux
Sniffing and spoofing are two common techniques to intercept and manipulate network traffic. Kali Linux offers a variety of commands and tools for sniffing and spoofing detection. Look over some of the commonly used sniffing and spoofing commands and tools listed below.
| Command |
Description |
| SIPp |
Test and benchmark SIP-based VoIP systems |
| rtpbreak |
Detect, reconstruct, and analyze RTP sessions |
| SIPVicious |
Audit SIP-based VoIP systems |
| rtpmixsound |
Mix audio into RTP streams |
| bettercap |
A Swiss Army knife for network attacks and monitoring, including sniffing, spoofing, and MITM attacks |
| DNSChef |
A DNS proxy that can be used to forge DNS responses and redirect traffic to malicious sites |
| fiked |
A fake IKE daemon used for launching MITM attacks against IKEv1-encrypted connections |
| hamster-sidejack |
Perform session hijacking attacks against web applications |
| HexInject |
Craft and inject packets into a network |
| iSMTP |
Test the security of SMTP servers by sending a large number of emails |
| isr-evilgrade |
Exploit software vulnerabilities and perform automatic updates of malicious software |
| mitmproxy |
A SSL-capable intercepting proxy used for intercepting, modifying, and replaying traffic between clients and servers |
| ohrwurm |
Generate payloads and test the detection capabilities of antivirus software |
| protos-sip |
Test the security of SIP-based VoIP systems |
| rebind |
Perform DNS rebinding attacks against web applications |
| responder |
Steal NTLMv1/v2 hashes and perform LLMNR/NBT-NS poisoning |
| rtpinsertsound |
Insert audio into RTP streams |
| sctpscan |
Perform SCTP network scanning and fingerprinting |
| SIPArmyKnife |
A tool used for testing the security of SIP-based VoIP systems |
| SniffJoke |
Manipulate network traffic in real-time |
| VoIPHopper |
Detect and exploit VoIP security vulnerabilities |
| xspy |
Monitor and analyze X11 traffic |
| zaproxy |
Test the security of web applications by scanning |
Kali Linux Reporting Tools
It is essential to generate an accurate report of penetration testing and provide it to clients and stakeholders for mutual understanding about the security risk of a system. Kali Linux has tools like Dradis, MagicTree etc. for managing, visualizing and reporting results of penetration testing.
| Command |
Description |
| CaseFile |
Create diagrams and charts to aid in the organization and visualization of data during investigations |
| cherrytree |
A hierarchical note-taking application that allows the creation and organization of notes and code snippets |
| CutyCapt |
Capture screenshots of web pages from the command line |
| dos2unix |
Convert DOS-style line endings to Unix-style line endings in text files |
| Dradis |
A collaboration and reporting platform for security testing professionals |
| MagicTree |
Visualize and analyze data from different sources, such as file systems, network traffic, and databases |
| Nipper-ng |
A tool used for auditing network device security configurations |
| pipal |
A password analyzer and cracking tool used to identify weak passwords |
| RDPY |
Perform remote desktop protocol operations, such as screen capture and input injection |
Password Attacks in Kali Linux
Different types of password attacks are common for hackers to gain unauthorized access to systems or networks. Using tools and commands of Kali Linux, professionals can test security and vulnerabilities related to passwords.
| Command |
Description |
| BruteSpray |
Automate password spraying attacks against multiple hosts simultaneously |
| CeWL |
Generate custom wordlists for password cracking and other security assessments |
| chntpw |
Reset passwords on Windows systems by modifying the Windows registry |
| CmosPwd |
Recover CMOS passwords on Windows systems |
| creddump |
Extract password hashes and other credentials from Windows systems |
| crowbar |
Brute-force attacks against remote authentication services |
| crunch |
Generate custom wordlists for password cracking and other security assessments |
| findmyhash |
Identify the hash algorithm used to encrypt password hashes |
| gpp-decrypt |
Decrypt Group Policy Preferences (GPP) passwords on Windows systems |
| hash-identifier |
Identify the type of hash used to encrypt password hashes |
| Hashcat |
A tool used for advanced password cracking and recovery |
| HexorBase |
A tool used for database management and exploitation |
| THC-Hydra |
Brute-force attacks against remote authentication services |
| John the Ripper |
A tool used for password cracking and recovery |
| Johnny |
A graphical user interface for John the Ripper password-cracking tool |
| keimpx |
Exploit vulnerabilities in Microsoft Windows systems |
| Maskprocessor |
Generate custom wordlists based on specified criteria |
| Ncrack |
Brute-force attacks against remote authentication services |
| oclgausscrack |
Advanced password cracking and recovery on systems with OpenCL-compatible hardware |
| ophcrack |
Password cracking and recovery on Windows systems |
| PACK |
Advanced password cracking and recovery |
| patator |
Brute-force attacks against multiple protocols and services |
| phrasendrescher |
Generate custom wordlists based on natural language patterns |
| polenum |
Retrieve password policy information from Windows systems |
| RainbowCrack |
Advanced password cracking and recovery using rainbow tables |
| SecLists |
A collection of various security-related wordlists for password cracking and other security assessments |
| SQLdict |
Generate custom wordlists based on SQL queries |
| Statsprocessor |
Generate custom wordlists based on a statistical analysis of existing passwords |
| THC-pptp-bruter |
Brute-force attacks against PPTP VPNs |
| TrueCrack |
A tool used for advanced password cracking and recovery |
| wordlists |
Collection of various wordlists for password cracking |
Maintaining Access in Kali Linux
A list of useful Kali Linux tools and commands for bypassing security measures and maintaining access to a system is below.
| Command |
Description |
| CryptCat |
Create encrypted and authenticated connections between two hosts |
| Cymothoa |
Inject shellcode into a running process in order to gain remote access |
| dbd |
A backdoor daemon that allows remote access to a system via a network connection |
| dns2tcp |
A tool used to tunnel TCP traffic over DNS protocols |
| HTTPTunnel |
A tool used to tunnel traffic over HTTP protocols |
| Intersect |
Generate payloads for exploitation of vulnerabilities |
| Nishang |
Create and execute PowerShell scripts for penetration testing |
| PowerSploit |
Collection of PowerShell scripts for penetration testing and other security assessments |
| pwnat |
Bypass NAT firewalls and establish direct connections between two hosts |
| RidEnum |
Enumerate user accounts and groups on Windows systems |
| sbd |
Create a secure backdoor connection between two hosts |
| shellter |
Bypass antivirus software and other security mechanisms |
| U3-Pwn |
Exploit security vulnerabilities in U3 USB smart drives |
| Webshells |
Collection of scripts and tools used for remote access and exploitation of web servers |
| Weevely |
A web shell is used to gain remote access to web servers and execute commands |
| Winexe |
Remotely execute commands on Windows systems from a Linux or Unix host |
Conclusion
The Kali Linux commands are useful for testing the security of systems and networks and identifying vulnerabilities by attackers. I believe the compact list may become useful for professionals to recall perfect commands and employ proper tools whenever necessary. Please feel free to comment below if you find the list helpful or have any suggestions regarding it. Visit linuxsimply for the most useful articles and cheat sheets.
