This article aims to list relevant cryptocurrencies, and is the only article allowed to discuss altcoins specifically.

Currencies

Major

Bitcoin (BTC)

http://bitcoin.org/
blocks every 10 min
coin supply* 21 million coins will be available
difficulty adjustment* 2016 blocks
hashing algorithm SHA256d
Initial Reward 50 coins per block
Market Cap: $144,000,000 (Jan 5th, 2013)
Launch Date: January 3rd, 2009

Namecoin (NMC)

https://en.bitcoin.it/wiki/Namecoin
(merged mined with BTC)
https://github.com/vinced/namecoin
http://namecoin.info/
blocks every 10 min
coin supply* 21 million coins will be available
difficulty adjustment 2016 blocks
hashing algorithm SHA256d
Initial Reward 50 coins per block
Market Cap: ???? BTC
Launch Date: April 18, 2011

Litecoin (LTC)

http://litecoin.org/
blocks every 2.5 min
coin supply* 84 million coins will be available
difficulty adjustment 2016 blocks
hashing algorithm scrypt
Initial Reward 50 coins per block
Market Cap: 150,000 BTC
Launch Date: October 2011

Dogecoin (Doge)

http://www.Dogecoin.com/
blocks every 1 min
coin supply* 99 Billion coins will be available and 5 Billion added every year.
hashing algorithm scrypt
Initial Reward 1,000,000 - 0 (Random) coins per block
Market Cap: $56,000,000
Launch Date: December 2013

Peercoin (PPC)

http://ppcoin.org/
https://bitcointalk.org/index.php?topic=101820.0
blocks every 10 min
Coin supply* non-deterministic coins will be available
difficulty adjustment each block
hashing algorithm SHA-256
Reward varies on difficulty coins per block
Mining: Incorporates Proof of Stake coin Generation, contains central checksums to kickstart the protocol
Market Cap: ???? BTC
Launch Date: approx August 19th, 2012 (date of its whitepaper)
- The public design phase of this coin was very brief.

Mastercoin (MSC)

http://www.mastercoin.org
Coin supply: 619478.59338440 MSC
Launch Date: September 1, 2013
Blockchain: Uses Bitcoin for transport, storage and security, inherits Bitcoin Protocol properties
Extended Properties: Distributed Exchange, Savings & Guardian Addresses, Contracts for Difference, Smart Properties, User Currencies
Protocol: Master Protocol
Spec Github Repo: https://github.com/mastercoin-MSC/spec

New

Please put here any coins whose concept are new. If a coin is discussed for 6 months and launched yesterday, it is not new.

Hashcoin (HSC)

http://hashcoin.technology
Block reward: 1024 HSC
Block time: 10 seconds
Hashing algorithm SHA256d
Retarget: Every 720 blocks or every 2 Hours
Coin supply: 28.4 billion (28,401,840,000) total coins
Block reward halved every 9,467,280 blocks (~ 3 years)
Extended Properties: Decentralised Exchange, Real-time Payroll, Digitised Property Rights, Contract Rights & Intellectual Property Rights, Trading Locales, DNA Records, Patents, Shares.
Launch Date: April 27, 2014

Omnicoin (OMNI)

http://omni-coin.co
Block reward: 100 omnicoin
Block time: 600 seconds
Hashing algorithm SHA256d
Retarget: Every 720 blocks or every 2 Hours
Coin supply: 41 million (41,840,000) total coins
Block reward halved every 21000 blocks
Launch Date: May 8, 2014
Going Live: June 1,2014

Coino (CON)

http://www.coino.org
PoW algorithm: Scrypt
Block reward: 35 CON (First 140 Blocks only 1 Coin for instamine)
Block time: 25 seconds
Retarget: 1 Hour
Coin supply: 100 million total coins
Launch Date: January 18, 2014

RonPaulCoin (RPC)

http://www.ronpaulcoin.com
Blocks every 2 min
Coin supply 2.1 million total coins
Difficulty adjustment every block
Hashing algorithm scrypt
Initial Reward 1 coin per block
Block reward halved every 262k blocks (~ 4 years)
Launch Date: December 29, 2013

Betacoin (BET)

http://betacoin.org/
Blocks every 4 min
Coin supply* 32 million coins will be mined in ~ first 6 years + 0,39% annual
Difficulty adjustment* 6 blocks
Hashing algorithm SHA256d
Initial Reward 128 coins per block
Block reward halved every 126k blocks (~ 1 year)
Launch Date: October, 2013

Nxt (NXT)

http://nextcoin.org
Pronounced as "Next"
Blocks every 1 min
Designed as 100% PoS (Proof-of-Stake) system
Coin supply* 1 billion coins exist from the start distributed by 74 founding stake holders
Launch Date: September, 29, 2013

Globe (GLB)

http://www.globecrypto.com/
Blocks every 1 min
Difficulty adjustment 1 day
Hashing algorithm SHA256d
Initial Reward 10 coin per block
Block reward halved at 86.4k blocks, 5 coins per block thereafter, with 4% increase annually
Launch Date: December 06, 2013

Valutacoin(VAC)

http://valutacoin.com/
blocks every 10 min
coin supply* 21 million coins will be available
difficulty adjustment* 2016 blocks
hashing algorithm SHA256d
Initial Reward 50 coins per block
Launch Date: April 2014

Minor

ImperialCoin (IMP)

http://imperialcoin.pw
Multiple algorithms
SHA256, Scrypt, Skein, Qubit, Groestl algorithms
Not to be confused with IPC, a Scrypt only coin.
Blocks every 1 min
Coin supply is 1.024 billion
Created only by a 14 year old.
Launch Date: March 1, 2014

Megacoin (MΣC)

http://www.megacoin.co.nz/
https://forum.megacoin.co.nz
Block Target is 2.5 minutes
Block reward halved every every 420,000 blocks
25 coins per block
42 Million total coins
Difficulty changes every block

The implentation of the Kimoto Gravity well retargets difficulty every block. This keeps mining fair and secure for all miners and users of the coin, and prevents the rampant multipool abuse that was (and still is) common with most all other altcoins out on the market today.

Anoncoin (ANC)

https://anoncoin.net/
https://forum.anoncoin.net
Block Target is 3.4 minutes
Block reward halved every 306k blocks
5 coins per block
4.2 million total coins
Difficulty changes every block

Anoncoin's goal is to make the user more anonymous by providing built-in support for I2P and Zerocoin.

Franko (FRK)

http://www.frankos.org/
http://forum.frankos.org
Block Target is 0.5 minutes
Block reward halved every 22m blocks
0.25 coins per block
11.2 million total coins
Difficulty changes every 720 blocks

Franko is considered the crypto with the fairest adoption length. Accepted by over 50 merchants and 10 brick and mortar stores.

Base currency used by the Franko Collective, a democratic group of developers.

FeatherCoin (FTC)

http://feathercoin.com/
A fork of Litecoin
243 million total coins

CraftCoin (CRC)

http://craftcoin.net/
Based on Litecoin
Portable in-game currency for Minecraft Servers
206,847 total coins

Tonal Bitcoin (TBC)

Tonal Bitcoin
(merged mined with BTC)
(blockchain shared with BTC)
(automatically converted to/from BTC)
blocks every 10 min
Coin supply* 7.8 tam coins will be available
difficulty adjustment 2016 blocks
hashing algorithm SHA-256
Initial Reward 1,2905.2 coins per block
Market Cap: $144,000,000 (Jan 5th, 2013)
Launch Date: January 2rd, 2011

IxCoin (IXC)

https://bitcointalk.org/index.php?topic=36701.0
(merged mined with BTC)
blocks every 10 min
Coin supply* 21 million coins will be available
difficulty adjustment 2016 blocks
hashing algorithm SHA1
Reward 96 coins per block

Devcoin (DEV)

https://bitcointalk.org/index.php?topic=34586.0
(merged mined with BTC)
blocks every 10 min
coin supply* constant generation coins will be available (???)
difficulty adjustment 2016 blocks
hashing algorithm SHA256d
Reward 50,000 coins per block
EXTRA 90% block subsidy goes to foundation

Freicoin (FRC)

http://freico.in/
http://www.freicoin.org/
https://bitcointalk.org/index.php?topic=89843.0
https://bitcointalk.org/index.php?topic=3816.0
blocks every 10 minutes
coin supply* 100 million coins will be available
difficulty adjustment 2016 blocks
hashing algorithm SHA-256
Arithmetically decreasing reward
EXTRA:

-- 4.89% annual demurrage
-- 80% block subsidy goes to foundation for the first 3 years (about 500 coins for each of first 161280 blocks, total 80m)
-- [u]In need of Dev work on daemon, client etc but network still running[/u]

I0coin (I0C)

https://bitcointalk.org/index.php?topic=36425.0 ; https://github.com/kr105rlz/i0coin
Perhaps should be moved to Dead section?

Terracoin (TRC)

http://terracoin.org/
blocks every 2 minutes
coin supply* 42 million coins will be available
difficulty adjustment 30 blocks
hashing algorithm SHA-256
Reward 20 coins per block

Liquidcoin (LQC)

https://bitcointalk.org/index.php?topic=60026.0
blocks every 10 minutes
no cap as block subsidy has a minimum of 1 coin
Constant difficulty of 0.5
Coin reward drops over time

BBQCoin (BQC)

http://blog.bbqcoin.org http://www.bbqcoin.com
blocks every 1 minute
coin supply* 88 million coins will be available
difficulty adjustment 60 blocks
hashing algorithm Scrypt
Reward 42 coins per block

BitBar (BTB)

http://bitbar.biz/home
blocks every 10 minutes
hashing algorithm Scrypt
Reward 1 coin per block
Coin reward drops over time

Netcoin (NET)

Main - http://netcoin.org.uk/
Forums - http://forum.netcoinfoundation.org/
blocks every 1 min
coin supply* 320.6 million coins will be available
difficulty adjustment* 60 blocks
hashing algorithm Scrypt
Initial Reward 1024 coins per block
Reward Halves Every 3 months or 129,600 Blocks
Market Cap: approx. $200,000 (Dec 4th, 2013)
Launch Date: Sept 2nd, 2013

GoldCoin (GLD)

http://gldcoin.com/
https://www.gldtalk.org/
https://bitcointalk.org/index.php?topic=317568.0
blocks every 2 minutes
coin supply* 123 million coins will be available
difficulty adjustment* 60 blocks
hashing algorithm Scrypt
reward 45 coins per block

Bytecoin (BCN)

BCN https://bytecoin.org
CryptoNote technology https://cryptonote.org/
Algorithm: CryptoNight
Started on July 4, 2012
Block time: 120 seconds (2 minutes)
Difficulty retargets each block
Block reward decreases each block according to the formula: BaseReward = (MSupply - A)/2^18, where MSupply = (2^64 - 1) atomic units and 'A' is amount of already generated coins
Total 184.46 billion BCN
Bytecoin is not a fork Bitcoin
Forum https://bitcointalk.org/index.php?topic=512747.0
Forum https://cryptocointalk.com/forum/1362-bytecoin-bcn/
Twitter https://twitter.com/Bytecoin_BCN
Coin features:

-- True anonymity & data protection
-- Untraceable payments use ring signature
-- Unlinkable transactions with random data by the sender
-- Blockchain analysis resistant
-- Only CPU-mining & ASIC-resistant
-- POW mechanism is a voting system for users

Dead / dying

MMM MMMcoin

dead

Weeds

[1]

Beertoken

[2]

Comparison of cryptocurrencies