The initial source comes from sdcuike/issueBlog#4
https://github.com/PacktPublishing free to download books code by Packet
https://github.com/EbookFoundation/free-programming-books Very immense
http://www.ituring.com.cn/book?tab=free Turing free books
http://ebook3000.com/Programming/index.html Not just it ebooks, including other areas, has ads
http://ebook-dl.com Either download or see films, interesting
https://scanlibs.com BAD ! download interval time is restricted
http://www.java1234.com/a/javabook/ Chinese site
https://www.iteblog.com/archives/category/ebooks/ focus on big data
https://www.packtpub.com Publisher
https://www.packtpub.com/packt/offers/free-learning One free book per day
http://www.oreilly.com/data/free/archive.html
https://www.pdfdrive.com Very Good ! many areas
http://ebook3000.com/Programming/index.html
http://proglang.informatik.uni-freiburg.de/teaching/concurrency/2014ws/
http://www.colorado.edu/cs/computer-science-course-archive
http://mindview.net/Books/DownloadSites/
http://inventwithpython.com/#invent
http://www.mhprofessional.com/
https://github.com/justjavac/free-programming-books-zh_CN
http://www.ituring.com.cn/book/ebook
http://itmanagersinbox.com/1875/13-sites-to-download-free-ebooks/
http://www.lemis.com/grog/Documentation/Lions/
http://www.tcpipguide.com/free/t_TCPConnectionTermination-2.htm
http://www.freesoft.org/CIE/Course/Section4/11.htm
https://landing.google.com/sre/book/
https://bushkarl.gitbooks.io/spring-cloud/content/
http://www.sonatype.org/nexus/resources/resources-book-links-and-downloads/
https://books.sonatype.com/mvnref-book/reference/index.html
http://book.huihoo.com/maven-the-definitive-guide/index.html
http://www.commandprompt.com/ppbook/ Practical PostgreSQL
http://use-the-index-luke.com/sql/table-of-contents SQL Performance Explained
http://math.hws.edu/javanotes/
http://aosabook.org/en/index.html The Architecture of Open Source Applications
Mi portal for official procedures such as loans, tax returns, and employment verification. The platform offers secure access to salary records from recent years, allowing users to manage their salary information easily and efficiently.