pdf2htmlEX --- Best Tool to Convert PDF to HTML

pdf2htmlEX is a free and open source command line tool to convert PDF files to HTML. pdf2htmlEX can convert PDF elements into corresponding or closest HTML5 elements for rendering in a web browser. It has very good support for all kinds of PDF files, just check the following amazing examples:
Typography: http://coolwanglu.github.io/pdf2htmlEX/demo/geneve.html
Formulas: http://coolwanglu.github.io/pdf2htmlEX/demo/cheat.html
Magazine: http://coolwanglu.github.io/pdf2htmlEX/demo/issue65_en.html

A quick start guide for using the tool: https://github.com/coolwanglu/pdf2htmlEX/wiki/Quick-Start

Official Site: http://coolwanglu.github.io/pdf2htmlEX/

Similar tools:
https://mozilla.github.io/pdf.js/
http://pdftohtml.sourceforge.net
https://poppler.freedesktop.org

Pandoc --- a universal document converter

Pandoc is a free and open source command line tool to convert documents from one format to another. It runs on Windows, macOS, Linux and supports many file formats including HTML, Word, EPUB, LaTeX, PDF, Markdown and so on. You can try it online at: https://pandoc.org/try/

Official Site: https://pandoc.org

JDownloader --- a free download management tool

JDownloader is a free, open source download management tool based on Java and running on almost all platforms, including Microsoft Windows, Linux, Mac. It supports direct downloading from various file hosting services, such as Rapidshare, Depositfiles, Mediafire, Qshare, Zshare, Openload, ..., and you can also use your premium accounts of these file hosting services.

Using JDownloader, you can bypass ads, CAPTCHAs and many other "free download" limitations imposed by file hosting services. For example, you can download several files simultaneously over several connections and save waiting time with hosts which limit downloads to one IP address. Other great features include clipboard monitoring, pausing and continuing of downloads, file integrity verification, and auto-extract compressed archives (e.g., RAR).

Official Site:
http://jdownloader.org

A List of JavaScript Cryptocurrency Miners

JavaScript based cryptocurrency miners can be embedded in a web page as a replacement for advertisement to monetize your websites. When users are visiting the page, the embedded JS code will run in background and mine the cryptocurrency for you. (Last Update: 2019/3/14)

CoinHive (discontinued)
Cryptocurrency: Monero
Minimum payout threshold: 0.05 XMR (~$4) 0.02 XMR
(payments fee: 0.005 XMR if less than 0.5 XMR)
Revenue sharing: 70% (you)
Note: Also supports Link Forwarding and Proof-of-work CAPTCHA.

GridCash (Site Down)
Cryptocurrency: Monero
Minimum payout threshold: 0.004 XMR or 1 WMZ (WebMoney)
Revenue sharing: 70% (you)
Note: Provide easy to use PHP+JS code to bypass blockings.

JSECoin (non cpu intensive)
Cryptocurrency: JSECoin
Note: See also http://www.miscool.ml/2017/10/jsecoin-javascript-based-cryptocurrency.html

Crypto-Loot
Cryptocurrency: Monero & uPlexa
Minimum payout threshold: 0.3 XMR or 5000 UPX
Revenue sharing: 88% (you)
Note: It has self-hosting option + CNAME Proxies instead of using its server hosted JS library.
Note: Currently the best alternative to CoinHive. Now it supports Link Forwarding (shortlinks) and Proof-of-work CAPTCHA.

Coin Have (Site Down)
Cryptocurrency: Monero
Minimum payout threshold: 0.5 XMR (~$50)
Revenue sharing: 85% (you)
Note: It also supports web extension.

CloudCoins (Site Down)
Cryptocurrency: Monero
Revenue sharing: 85% (you)

HashforCash (Site Down)
Cryptocurrency: Monero
Revenue sharing: 95% (you)

Minero (Site Down)
Cryptocurrency: Monero
Revenue sharing: 98% (you)

ProjectPoi (Site Down)
Cryptocurrency: Monero

Inwemo (Site Down)
Cryptocurrency: Monero

MoneroMiner
Cryptocurrency: Monero

Simplecoin
Cryptocurrency: Pay in Clam or Dogecoin

CoinIMP
Cryptocurrency: Monero & Webchain
Payout: 97% if advertisement is enabled, 90% if advertisement is disabled

Others (CoinHive pool with low payment threshold, e.g., to FaucetHub):
DogeMiners (Site Down)

Cryptocurrency: Pay in DogeCoin via FaucetHub
http://ad-miner.com (Site Down)
https://minehub.online (Site Down)
http://u2cloudmining.winspiral.net/monero_mining.php
http://minercoin.net (Site Down)
https://mineiota.com/ (minimal payout: 1 IOTA)

Links:
https://github.com/cryptonoter/CryptoNoter
https://coinhive-proxy.party
https://github.com/x25/coinhive-stratum-mining-proxy (Python)
https://github.com/cazala/coin-hive-stratum (Node.js)
https://github.com/keraf/NoCoin
http://monerominer.life
http://www.socketminer.com
https://brominer.com
http://www.monero-miner.com
https://www.webminerpool.com

draw.io --- A free open source online diagram drawing application

draw.io is a free and open source online diagram drawing application. Just visit https://www.draw.io and begin to draw your diagrams. There is no need for registration or login and you can import existing diagrams from or save your creations to your local drive or online storage services such as Google Drive, Github, Dropbox, One Drive and Trello. draw.io can also work as a Google Docs add-on. It supports many formats, including PNG, JPEG, PDF, SVG, VSDX (Microsoft Visio), HTML and XML.

HTTrack Website Copier --- Download Websites for Offline Viewing

HTTrack is a free (open source) and simple offline browser utility working on both Windows (WinHTTrack) and Linux (WebHTTrack).

You can download/cache a website from Internet to a local directory by inputting the website URL and then browse the site offline without Internet connection as if you were viewing it online. It automatically arranges the original structure of relative links for the cloned website and is also able to monitor and update an existing mirrored site.

Official Site: http://www.httrack.com/page/1/en/index.html