Read and understand https://ripple.com/ripple-gateways.pdf if you want to run your own gateway, otherwise convince soemone to do it for you.

It exists since about a year now: https://github.com/ripple/rippled

Which parts of Ripple don't you understand? Just like with Bitcoin, some people don't get mining while others don't know how to operate their wallet software...

Why shouldn't it be decentralized? You sound a lot like someone reading ripplescam.org but not really understanding what's written there is a mixture of bullshit (a hint: BitTorrent is NOT distributed at all), statements out of context and misinformation, paired with a very carefully selected range of comments.

I liked the more casual "primer" white paper at https://ripple.com/ripple_primer.pdf - if you have more concrete questions after that, please ask them, as you actually did not ask a real question so far...

No, Ripple is a decentralized exchange, bitcoin is a digital asset. If you want to buy a digital asset that is native to Ripple, you can buy some XRP (confusingly called "ripples"). You can do so on various sites which I haven't really used so I'm not going to list them here, sa it might sound like a recommendation.

I'd rather have my money relax for 2-3 days than to enter a fixed rate loan at current rates... but that's up to the lending market of course, some people seriously seem to have an itch to use just whatever rate they can get as soon as they might be able to lend out something.

Once we jump on the roller coaster towards 1000 or 500 USD again, it might get more interesting. Also, a lot of kids probably get money on christmas, might be useful to have some positions in line for that?

Is it a mask?

It would be much easier to act as gateway to (and maybe from) Ripple and make markets in there yourself than to code a whole exchange. Take a look at DividendRippler for inspiration. This would give your customers access (if you make a market or find people who make them for you) to even cashing out USD or buying your beloved DOGEcoins with BTC. So wow!

Can you name a few of these "standards" that you are allowed to use without reverse engineering a closed server component and that are supported by major forex trading software?

Magnet links still just point to a torrent file that has been stored in the mainline DHT instead of a centralized source like thepiratebay.
If you turn off DHT and just have the magnet link (actually you anyways just need the info hash (the btih part)) you are completely helpless, even though you'd find people offering you the file for download!

There are already people showing up to arbitrage on Ripple. There is at least one US based gateway (PeerCover) that even accepts credit card payments, so I don't really see difficulty there getting USD in and out. BTC anyways are easily accessible within Ripple, depending on market situations I'd recommend though not to buy in huge market orders - after all the BTC market is about 1% the volume of Bitstamp.

Once you have USD in Ripple, you can trade BTC and withdraw them to any BTC address (if Bitstamp's bridge doesn't stall again, sometimes it does, usually it doesn't) in about 10 seconds flat.

Bitcoin currently depends on exchanges, if you take these away, both Coinbase and BitPay (who process a LOT of transactions on the block chain) are out of business in one single swipe. Bitcoin can still continue to exist, but will have very limited usability without exchanges.

Ripple would take over in that regard, that you do not need to exchange anything as gateway yourself - you only offer to do AML/KYC and deal with deposits and withdrawals of whatever currency or asset you like, that's it. Every exchange to whichever obscure currency that actually happens is distributed inside the system and out of reach for any government interference.

The proof for that destruction still somehow needs to reach Ripple but that's one possible way to do it, yes. It is actually quite hard to really "destroy" BTC in a sane way - spending as fee doesn't count, otherwise miners could spend their own coin as fees all day long. If you just send dust to the bitcoineater address, you'll spam the UTXO set with unprunable stuff.
Maybe by tracking coins you could do something like colored coins for every single satoshi, so over time people can spend them as fee and still redeem only the 2 100 000 000 000 000 units that exist in BTC land.

Any business that accepts BTC actually accepts Ripple already, since there is a bridge towards it, so using Ripple you can pay far more merchants than you might think. The nice thing is that you can do a "reverse BitPay" for example at the moment, by holding fiat and paying someone in BTC (maybe if you don't like the volatility or are bearish, yet still your favourite web shop only accepts BTC). Also you can hold e.g. LTC and stil pay anywhere BTC is accepted at current rates, even though something like "LitePay" doesn't (yet?) exist.

Depends of course on the exact attack - some transactions would easily be seen as fake, others might be more difficult.

Nope, you are assuming that the rules in Bitcoin-QT are actually enforced by some protocol - this is NOT the case. They are merely guidelines (that a lot of miners currently follow though).
Similar rules probably also could be laid out for Ripple if really needed, so far destroying XRP was enough though to keep spammers away.

If anyone REALLY wanted to harm Bitcoin and got their hands on a million or 100k of them, they should better simply buy mining equipment for that money, it is MUCH cheaper to attack using minig power than using transactions.

I'd just let the open market decide if you can't come up with the ideal frequency (and I don't see a way how you could do that).

As far as I understand it, feeds anyways would be transactions in the Bitcoin network, so you'd need to use transactions which (if mined) will cost mining fees. If someone wants to send an update every 2 seconds, he'll quickly run out of funds then...

If for whatever reason they don't want to use the Bitcoin block chain for that transaction, they need to use 1/100 000th of 1 XRP to pay for the transaction fees on Ripple. Otherwise people would simply spam the ledger for fun.

These fees cannot be taken out of IOUs, because these are by definition not even existing as assets on the network, they exist only at the gateways. The only native asset to Ripple are XRP.

It might be possible to build a connection to BTC (it would need to be direct by the way, so you'd need to run a trustworthy Bitcoin client and a rippled) and to have some kind of proof that you paid some amount of BTC instead of destroying XRP to ensure non-spammyness.

Ripple's real use case is by the way not 2 people anyways using BTC - the really nice thing is that you can use whatever currency you want (e.g. BTC) while your counter party can receive whatever they want (e.g. USD). Ripple is much closer to BitPay than to Bitcoin.

Edit:
Depends on the form of DoS, if they spam meaningless transactions they could keep it up a quite long time I guess, though it wouldn't be too hard to just ignore that or simply dealing with it. They can spam the AccountState (similar to Bitcoin's UTXO set) but thanks to funding limits (which would be simply manually increased by independent rippled validator operators) this has a finite size. If they DoS attacked all known rippled servers out there, they might drive them to connect through VPNs and TOR, just like with bitcoin.

If the US government seized all BTC from Mr. Silkroad and mounted a DOS attack on the Bitcoin network, how long could they keep it up?

No, I mean the wallet in the sense of what for example your bitcoin wallet is: A client that is able to sign transactions using one or several private keys that have access to funds.

I think you talked mainly about b) (the money that gets locked away in the vaults of a gateway) while mmeijeri talked about a) (the wallet software where you see all the balances you have with one or several gateways + your XRP balance).

Someone did (nearly exactly) that, already months ago:
https://bitcointalk.org/index.php?topic=149533.0

As soon as the moeny is moved, the transfer fee is charged, placing an order can move it (if it is immediately taken) or it can just stay and wait (if you try to sell 1 BTC for 5000 USD for example). In the latter case the transfer fee will apply after it actually moves, if you withdrwa that order in the meantime, nothing is charged (besides some tiny amounts of XRP, as with any transaction).

Wenn Name und Anschrift draufstehen, ja.

Well, then go grab some of these "thousands"? Bitstamp even operates a bridge towards BTC, so you can cash them out immediately (well in 5 seconds on average...) to BTC if you like.

Are there really people that are surprised that a random unbacked commodity can have significant value quickly in this forum?!

Currently ~250 are 0.01 BTC: http://bitcoincharts.com/markets/rippleXRP.html
They actually were worth a lot more in summer and tanked quite a bit after that.

Edit:
Yes, XPM is Primecoin, I guess nahtnam wanted to say XRP but had another currency code in his muscle memory...

Edit2:
You seem to combine 2 things:
a) the Ripple wallet (which is a client written in JavaScript, similar to the one offered by blockchain.info)
b) actual assets that get deposited at gateways (USD, BTC, gold bars, silver dimes, hours of work...)

a) is the stuff you access when going on ripple.com/client
b) can be stored online (depends on the asset), or (more likely) offline.

The Ripple network itself is distributed, anyone can run a node. The gateways (meaning the entities that actually store someone's "stuff") are more along the definition of decentralized (which is NOT what's depicted on ripplescam.org by the way!), similar to the bitcoin network and it's exchanges as "hubs". This is on a different layer of the network though, not at the protocol, but more at the actual usage part.

I'm willing to sell you small amounts of XRP at market rates for BTC if you need some to start (up to about 200, which is about 0.01 BTC currently), other than that you can buy them at Kraken, Bitstamp and some slightly more shady places. Also there are some people just giving them away if you promise to buy a few more and give these away to other newbies in return (I don't know how successful this stuff really is in the end, that's why I usually just sell them).

I don't like the currency much either, unlike bitcoins though XRP are just a small part of the system and can be mostly ignored if you don't explicitly want to use them to make markets.

That's exactly what runs at https://ripple.com/client/ yes.

The server component it connects to (see https://ripple.com/client/#/options) is the server called "rippled" from https://github.com/ripple/rippled. If you want to modify it so it uses BTC instead of XRP as native asset (I'd recommend adding BTC as alternative instead of replacing XRP, but that's up to you) you need to work on that first, not the client which is more or less a dumb frontend for an untrusted API provider.

Just like with Bitcoin alt-coins just please think of an original name for your project and use that throughout your fork, similar to every coin that is not on the Satoshi block chain should not call itself "Bitcoin", any distributed marketplace that does not run on the OpenCoin/RippleLabs ledger chain should not call itself "Ripple".

It would be really cool to see some forks in the wild by the way, if you need any help I'd recommend jumping over to the ripple.com forums though, the churn rate in this forum section (+ the amount of "DOGECOIN IS TEH AWSUM! WOW ! SO COIN!" posts) is a littel bit too high for more technical discussions.

Just for you (it was already posted in this thread):

To build your own working Ripple network, you need at least 1 rippled server, code at:
https://github.com/ripple/rippled

That's it already, but I guess you want some infrastructure with it?

Then you likely want to have a client instead of writing your own, you can use the one at:
https://github.com/ripple/ripple-client (written in JavaScript)
or you can write your own either using the API or one of these 2 libraries:
https://github.com/ripple/ripple-lib-java (Java)
https://github.com/ripple/ripple-lib (JavaScript)

If you want to store the encrypted blobs for your customers (so they can switch computers and still access their wallets in a secure way) you can set up this server too:
https://github.com/ripple/ripple-blobvault

Afterwards you might want to publish your trades to bitcoincharts.com? There's some code for that!
https://github.com/ripple/ripple-chart

Bitcoincharts is operated by MtGox and closed source though... you'd rather have your own charting website, fully Open source, right?
https://github.com/ripple/ripplecharts


Oh, by the way I operate my own rippled server already for quite some time now, after you know how to compile it (...it is a single command) and where to find the binary then it's smooth sailing from there.

Edit:
ripple.com as in the HTML code for the website?! Or do you actually mean ripple.com/client - the code for that is linked above.