For chess aficionados out there! Here's some free (and legal I think) chess softwares to improve your game. If you want to improve your game and not spend a cent read on. The short list includes playing softwares, database, and training softwares.
1.) Arena 2.0.1
Arena is a graphical user interface. You can organize engine tournament in this software. Most importantly you can play against chess engines (both Winboard and UCI). Arena have the features other commercial softwares have like position set-up, limiting engine strenght, opening books, and others. You can also use this software to analyze games (but make sure you use a strong engine). You can also install engines in this software. I currently have 17 engines in my Areana. This is really a must have (especially if you don't want to spend money like me).
Crafty is a chess playing software with its own graphical user interface. But you can still play Crafty in Arena or other shell. The GUI of Crafty is very good looking. And Crafty is (as I have read and heard) one of the strongest engines out there. This software also have some features like you can see on other playing chess softwares. Crafty is good for the serious-type-chess player and club players alike. And you can download this engine for free.
3.) Nagasaki (version 5)
Nagasaki is a chess playing software similar to Crafty. This playing chess software includes basic features seen in the Crafty GUI. The downside of this chess software is that its GUI is not that good looking (for me) and that the engine is not that strong (for analysis and for strong players). But this is very good for club players, novices, and beginners. You can also limit the playing strenght of the engine to meet your level.
4.) Fritz 5.32
This is one of the best free chess softwares out there. Chessbase gave out this version of Fritz for free. This engine is very strong but you can also play in sparring mode/hadicap mode. You can add opening books and this software also includes a lower version of Chessbase database (with no games included). Fritz 5.32 can also open files in Chessbase format. This is also a must have.
5.) Chess DB
Chess DB is a free chess database. Aside from its database use, you can also save your own games in a way where the right game can be quickly found, a very time-efficient method to study, which will give the maximum improvement in the minimum time, and access to statistics about both your own games and of GMs, which would be impractical to collect without a computer based chess database. You can save, annotate, analyze (with strong egines), create tournament crosstables, and play (also) in this software. The only thing I don't like in this software is that it is not really a user friendly software. I had a hard time learning to open and save a database.
6.) Chessbase Light 2007
This is also one of the best free chess softwares out there. Chessbase light is a crippled version of Chessbase 10. This is also a database software wherein you can access to game collections and allow you to manage them with ease. Very user friendly. This is also a must have.
7.) Chess Position Trainer
Chess Position Trainer is a software that focuses on chess opening, training, and reportoire management. This software is very good (although I prefer to study opening the traditional way) and very free. You can use this software to study openings and you can create your opening reportoire in this software. You can also train tactics in this software. You can also download openings in their website for training and study.
8.) Chess Tactic Sever
CTS is not really a software but a website. This website is for tactics training. You can train your tactics in this website. Once you register (ofcourse for free), you'll have your own rating. Your rating will increase as you solve more tactics problems. This is a very good site for training. I train in this website almost everyday and it really helps my tactical vision.
So these are just some of the free chess softwares I can recommend. These are good softwares and they are free for download. And these softwares are all legal copies. BTW, these softwares are good especially for club players or intermediate players. But for the serious-type-chess player (GMs), I think they need the commercial programs because these programs are much way more stronger. Just click the links above and download. There are also other websites on the internet like Zakron Fischer's site. There are lots of softwares in that site.