Linux online learning websites

1. Building Dynamic Websites at Harvard University

This online OCW course covers the knowledge needed to build a website. Consisting of various video lectures, this tutorial instructs individuals on how to build a website using Linux, as well as various other frameworks. Students learn how to set up domains, design databases, program with Java and build web pages using CSS (cascading style sheets) and XHTML (extensible hypertext markup language). There are sample projects in PDF format.

3. Computational Physics at Universiti Teknologi Malaysia

The focus of this course is to teach students how to do physics calculations using a computer as a calculator. They also learn Java programming in a Linux environment. Through external website links, this online course teaches students about using algorithms and working within the Linux operating system.

4. The Embedded Linux Quick Start Guide through YouTube

The free tutorial, which lasts less than an hour, provides learners with an introduction to the Linux environment. Narrated by Chris Simmonds at a 2010 Embedded Linux Conference Europe, this video is the first in a 3-part series on Linux. Students learn the four basic elements of Linux: toolchain, boot loader, kernel and user space.

5.Introduction to Linux at the University of South Carolina

A simple introductory tutorial of slides in PDF format, this course material shares basic information about what Linux is, the different versions – or distributions – available, and how to use it. Files, folders, pages, commands and writing script are some of the topics and tools this course covers.

6. The Linux Effect: 20th Anniversary at The Open University

Offered as an online podcast training, the Linux Effect offers information on the Linux operating system and how it’s advanced through the years. Students learn the origin of Linux, how Linux is used in our daily lives and the connection between Linux and cloud computing. Students need a PDF viewer, such as Adobe Reader, to complete this course.

7. LPI Exam 201 Prep: Linux Kernel at IBM

In this free tutorial series, users prepare for the Linux Professional Institute Intermediate Level Administration (LPIC-2) Exam 201. The first tutorial guides students through the components, compiling, patching and customizing of a Linux kernel. Other topics in the series include system maintenance, web services, hardware and troubleshooting.

Courtesy: Education-Portal


DoCircuits: Web-Based Online Simulator

There are plenty of circuit simulator software available in the market. But these software are not without their set of problems—these need to be downloaded and also need an expert to guide you side by side.—a virtual lab—puts an end to these problems by letting you build, simulate and share your circuits, entirely in your browser

12-watt audio amplifier

NOVEMBER 2012: Tired of going to the lab everyday to conduct your simulation tests? Well, worry no more! Debabrata Bagchi, CEO and founder, Sparsha Learning Technologies, has devised a very simple Web-based simulation centre for all your simulation problems— It is a virtual lab that lets you create, analyse and run analogue, digital and mixed-mode electronics circuits, entirely in your browser.

The world of electronic simulation
Electronic circuit simulation uses mathematical models to replicate the behaviour of an actual electronic device or circuit. Simulation software typically allows for modeling of circuit operation and is an invaluable analysis tool. Due to its highly accurate modeling capability, it is widely used for teaching purposes in technical institues.

The software engages the users by integrating them into the learning experience. These kinds of interactions actively engage learners to analyse, synthesise, organise and evaluate content, and result in learners constructing their own knowledge. It is, undoubtedly, imperative that an electronics engineer be well versed in the fine art of simulation.

Simulating a circuit’s behaviour prior to building it greatly improves design efficiency by making faulty designs known as such, and providing insight into the behaviour of circuit designs. In particular, for integrated circuits, the tooling is expensive, breadboards impractical, and probing the behaviour of internal signals extremely difficult. Therefore almost all the IC design relies heavily on simulation. The most well known analogue simulator is SPICE, while on the digital side, simulators based on Verilog and VHDL are the most commonly used.

The need for an online Web-based simulator
As mentioned above, there are plenty of simulator packages already available in the market. But there are several issues with the solutions offered in the simulation domain.

“The software need to be downloaded/installed. These have a steep learning curve—not to mention the need for an expert to be guiding you side-by-side. User-experience isn’t a priority with these software. The biggest trouble is that people who are just starting out in this field are in a position where they have to use high-end simulators. They need to get an in-depth knowledge before beginning the work,” says Bagchi.

R-2R ladder DAC

“DoCircuits is my way of letting the small guy play with electronics and get to know how fun it is. We wanted to make simulation easy and accessible for all. We wanted to make it more fun, and are looking at gamifying some of the features to make it more appealing to the younger crowd. We will be developing premium solutions for the enterprise market as well,” Bagchi adds.—An overview
DoCircuits is a cloud-based application that took around nine months to develop. Users go to and create a login. A single login allows them to create innumerable circuits. By clicking ‘Launch Virtual Labs,’ they can save these circuits on the cloud so that they can be accessed from anywhere. This allows the users to share their circuits with others.

When a user creates circuits and runs them on the cloud, results are processed from the cloud and shown to the user for analysis. The cloud backend is implemented over Microsoft Azure, while the front end is created in Flex. You can access the simulation features even without logging in. But to make use of the sharing and saving features, a login is necessary.

To top it all, this cloud-reliant solution is not very bandwidth-intensive as the only data transferred is the circuit and its simulation results. All the other information is in the browser itself. Since the simulation has been implemented on the cloud, there is no restriction on the number of people using it simultaneously.

“Our algorithms will scale up at the back end automatically. Hence you wouldn’t be handicapped by the speed of your connection,” says Bagchi.

The simplest ideas are usually the hardest to realise. Bagchi explains the challenges they faced: “The challenges we faced were mainly restricted to R&D—mostly in product design, creating load balancing algorithms on the cloud, creating models for new components, solving mathematical simulation problems for running large circuits, etc. Some of the other problems were related to the look of the final product. We had to go through a lot of changes regarding the features we allowed. We had to remove a few features because they didn’t offer anything functional to the product and were mostly an aesthetic addition. Thankfully, we didn’t face any problem that made us pull out our hair.”

Future plans
Product development and innovation is a continuous process. Bagchi shares the improvements that they plan for the future versions of their solution: “We are adding capabilities for pure digital simulation, supporting integrated circuits, learning and running Verilog and VHDL simulations along with the ability for more devices and components and analysis methods.”

From monetisation to patenting the technology, Bagchi has a pretty comprehensive roadmap planned for Do-Circuits. “We will be targeting global users, students and teachers in the next two years and target to have 100,000 active users using simulation by 2014. Post 2014 we will release our enterprise version for SMBs in the semiconductor space. We also see growth in using this solution for building experimential learning courses in electronics and hope to certify 50,000 students with this platform by 2014. Running the simulation online is currently free. Going ahead, we will introduce simulation as a service model for advanced simulation features and components. We have an offline version of the tool for the PC priced at Rs 1000 for a year’s licence,” Bagchi informs.

“We are currently in the process of patenting some of the technology used for the product. This is the age of cloud computing, cloud storage and so on. This is just the beginning of the cloud revolution,” he sums up.

Lightweight Linux Distros For Your Old PC

Puppy Linux

This is the smallest Linux distro at just 132MB download. The distro loads itself entirely into RAM on bootup, so is incredibly quick and responsive. However, if one wishes to use a modern browser, one would need 256MB. This is a truly portable distro, allowing the user to save documents to the same USB drive it boots from. The price one has to pay, however, is that OS seems resolutely old-school. The icons and desktop look like something from the 90s.

Peppermint OS Two

The OS is based on Lubuntu, which in turn was based on Ubuntu. The distro makes use of the LXDE desktop environment, but has been built keeping the cloud computing conundrum in mind. Inspite of the fact that the developers recommend one have at least 192MB RAM – 64MB more than the other distros here.

Macpup 528

This is a great choice for those who think that the Puppy Linux is too retro-ugly. The distro is based on Puppy Linux, so has the same big advantage – it runs in RAM so is incredibly fast and responsive. The cool thing however is that it has an aesthetic appeal. The window manager is Enlightenment, which is arguably the best-looking Linux window manager of all. There are even transparency effects and a fancy animated dock at the bottom for your programs.

Crunchbang Linux 10

Based on the Debian project, this distro uses the Openbox window manager. This in turn is one of the least resource-heavy there is, helping the OS boot in just over 30 seconds. Though it can run on 128MB of RAM, 256MB is recommended as well.

Lubuntu 11.10

Another distro that makes use of the lightweight LXDE desktop environment, this distro is even lighter than Xubuntu, which in recent versions has recommended you have at least 512MB RAM. Lubuntu, on the other hand, can run in 128MB RAM, but we’d recommend at least 256MB.


Πως μπορούμε να ιδρύσουμε μια καινοτόμο εταιρεία υψηλής τεχνολογίας χρησιμοποιώντας αποκλειστικά Ελεύθερο Λογισμικό

Η Εταιρεία Ελεύθερου Λογισμικού/Λογισμικού Ανοιχτού Κώδικα (ΕΕΛ/ΛΑΚ), στο πλαίσιο των δραστηριοτήτων της για τις ανοιχτές τεχνολογίες, την επιχειρηματικότητα και την καινοτομία,  συμμετέχει στο δίκτυο Enterprise Europe Network – Hellas (EEN – Hellas, Στο πλαίσιο αυτό παρουσιάζει την Logikon Labs. Η Logikon Labs είναι μια επιχειρηματική μικρομονάδα υψηλής τεχνολογίας η οποία ιδρύθηκε το 2012 με έδρα στην Αθήνα. Η εταιρεία προσφέρει καινοτομικές υπηρεσίες σχεδίασης και ανάπτυξης ενσωματωμένων ηλεκτρονικών και λογισμικού για επιστημονικές, βιομηχανικές και αεροδιαστημικές εφαρμογές. Κινητήρια δύναμη της Logikon Labs είναι η επιθυμία των ιδρυτών της να παρέχουν καινοτομικές λύσεις λογισμικού και ηλεκτρονικής για τις πλέον απαιτητικές εφαρμογές και αγορές, μέσα από μία μικρή, ευέλικτη ομάδα άριστα καταρτισμένων μηχανικών.

Τα τελευταία χρόνια είναι όλο και πιο προφανές ότι η καινοτομία στο χώρο της ηλεκτρονικής και του λογισμικού δεν απαιτεί κατ’ανάγκη κλειστά μοντέλα πνευματικής ιδιοκτησίας για να παράγει ένα βιώσιμο επιχειρηματικό μοντέλο. Αντιθέτως, υπάρχουν πολλές περιπτώσεις επιτυχημένης επιχειρηματικά «ανοικτής καινοτομίας» η οποία οδήγησε σε καλύτερα προϊόντα, μεγαλύτερες βάσεις πελατών, καλύτερη εταιρική προβολή και μείωση του κόστους ανάπτυξης. Οι άνθρωποι της Logikon Labs παρακολουθούν ενεργά όλες τις εξελίξεις του χώρου για περισσότερα από δεκαπέντε χρόνια με μεγάλο ενδιαφέρον, και είναι σήμερα σε θέση να προσφέρουν σαφή καθοδήγηση και λύσεις στον τομέα της ανοιχτής καινοτομίας.

Η Logikon Labs υποστηρίζει το Ελεύθερο Λογισμικό/Λογισμικό Ανοιχτού Κώδικα όχι μόνο στα έργα της, αλλά και σε όλη την τεχνική υποδομή, καθώς η εταιρεία χρησιμοποιεί σχεδόν αποκλειστικά Ελεύθερο Λογισμικό/Λογισμικό Ανοιχτού Κώδικα για όλες τις ανάγκες.

Αυτό εκτείνεται από το Debian GNU/Linux λειτουργικό που είναι εγκατεστημένο σε όλους υπολογιστές, στο Libreoffice και το Latex για τη δημιουργία εγγράφων και το για διαχείριση έργων, μέχρι το Kicad για σχεδίαση κυκλωμάτων και PCB.

Παραδείγματα ηλεκτρονικών συστημάτων των οποίων ο ηλεκτρονικός σχεδιασμός έχει γίνει 100% με ΕΛ/ΛΑΚ μπορούν τα βρεθούν στο

best open source ERP web-based applications

Enterprise Resource Planning (ERP) is, by definition, an integrated computer-centered system aimed at managing internal and external organization resources. Among the resources are: finance, human resources, materials as well as tangible assets. Simultaneously, ERP is an application and software architecture that increases the effectiveness of information flows between different business functions both inside and outside an organization, thus being an enterprise-comprehensive system of information. Thanks to a centralized database and working on a common computing platform, ERP unites various business operations into a homogenous system environment.

The following is a list of best open source ERP web-based applications:


OpenERP is an open source business applications suite: CRM, Purchase, Manufacturing, Warehouse Management, Project Management, Accounting, Human Resources, Marketing.


Openbravo ERP

Openbravo ERP is the web-based ERP for SMEs. Available as a professional open source ERP solution, Openbravo ERP provides unique high-impact benefits: Comprehensive, Innovative, Cost effective.


Opentaps Open Source ERP + CRM

Opentaps Open Source ERP + CRM is a fully integrated application suite that brings together top-tier open source projects to help you manage your business more effectively. Today, opentaps supports ecommerce, Customer Relationship Management, Warehouse and Inventory Management, Supply Chain Management, and Financial Management to Business Intelligence and mobility integration out-of-the-box.



webERP is a complete web based accounting/ERP system that requires only a web-browser and pdf reader to use. It has a wide range of features suitable for many businesses particularly distributed businesses in wholesale, distribution and manufacturing. It is developed as an open-source application and is available as a free download to use. The feature set is continually expanding as new businesses and developers adopt it.



Dolibarr is a modern and free ERP & CRM web software to manage your company or foundation activity (contacts, invoices, orders, stocks, agenda, …). It’s an opensource and free software designed for small and medium companies, foundations and freelances.



PhreeBooks accounting was developed as an open source ERP (Enterprise Resource Planning) web-based application written for the small business community. The goal is to provide a multi-language web-based end-to-end enterprise management tool. Written in the widely availalbe PHP scripting language with the robust MYSQL database engine, PhreeBooks goal is to provide a low cost solution for small business concerns. Unlike most commercially available accounting packages that use proprietary software or require MS Windows operating system, PhreeBooks is platform independent, browser independent and easily translated into many languages.



LedgerSMB is an open source, free ERP and financial accounting program. As of 1.3, it offers solid AR, AP, and GL tracking as well as inventory control and fixed assets handling. The LedgerSMB client could be a web browser (FireFox, Opera, Chrome, Explorer ++) on any platform or a programmed API call. LedgerSMB server works well on any UNIX-type platform, including Linux, *BSD, and Apple’s OS X. LedgerSMB server is tested on Windows although performance and scalability are believed to be stronger on UNIX-like platforms.



Apache OFBiz (The Apache Open For Business Project) is an open source enterprise automation software project licensed under the Apache License Version 2.0. By open source enterprise automation we mean: Open Source ERP (Enterprise Resource Planning), Open Source CRM (Customer RelationShip Management), Open Source E-Business / E-Commerce, Open Source SCM (Supply Chain Management), Open Source MRP (Manufacturing Resources Planning), Open Source CMMS/EAM (Maintenance Management System/Enterprise Asset Management), Open Source POS (Point Of Sale), and so on.



saltos_logoSaltOS is the Business Management solution 100% Cloud Computing. It integrates features like CRM and ERP. Moreover is it licensed as 100% free software GPL-3.0.



erp5_logoERP5 has been recognized, since the beginning as an innovative and outstanding ERP solution. Hence, the first deployment of ERP5 for Coramy, a European leader in the apparel industry, was awarded best ERP implementation project in the special edition of Décision Informatique in June 2004.
ERP5 is an Enterprise Resource Planning Solution published as Open Source which means transparency, flexibility and evolutivity for customers. It also means no risks of forced upgrades, guaranteed lifetime maintainability and of course no license fee and no requirement to stay with the same vendor or service company forever.



AdempiereLogoADempiere Business Suite is an industrial strength open-source software solution that combines ERP, CRM and SCM support for business process. ADempiere provides a framework for extending and customizing to meet business needs.



php tricks

1. PHP Predefined Variables

PHP indeed has a huge number of predefined variables that it provides for a script. Here’s a list!

2. PHP Regular Expression

Here you will learn about the three sets of functions that PHP has, which allow you to work with regular expressions.

3. PHP Error Handling

W3Schools brings you a tutorial on error handling using PHP.

4. PHP Bugs Debugging

This web page explains the reasons for some of the most common bugs that come up in PHP programming.

5. PHP Date & Time

This web page is about the powerful date arithmetic tools that PHP provides.

6. PHP and MySQL

This is a list of MySQL functions for PHP from the official documentation of PHP.

7. PHP and AJAX

This web page will show you how a web page can interact with a server, while the user is typing in a query.

8. PHP and XML

This is the official documentation from the PHP website on XML Parser.

9. PHP Object Oriented

Object oriented programming concepts are important for any programmer. Here is a web page that will help you with them for working with PHP.

10. PHP for C Developers

PHP is very similar to C, but with untyped variables and a lot more web-based programming functions.

11. PHP for PERL Developers

In this you will find some of the biggest similarities as well as differences between PHP and Perl.

12. PHP, AJAX and MySQL together

This example demonstrates how a web page can get information from a database using AJAX.